Answer:
The average atomic mass of Y is 123.4725 g/mol
Explanation:
The average mass of an element is calculated by taking the average of the atomic masses of its stable isotopes.
The enitre atomic mass = 100 % or 1
⇒ this consists of 57.25 % atoms with mass 123.90 g/mol
57.25 % = 0.5725
⇒ this consists of 42.75 % atoms with mass 123.90 g/mol
42.75 % = 0.4275
To calculate the mass of this isotope we use the following:
0.5725 * 123.90 + 0.4275 * 122.90 = 123.4725 g/mol
plz help!!
A group of students performed an experiment to prove the law of conservation of energy. In the experiment, a flask containing water at room temperature was shaken vigorously for a few minutes. The table shows a partial record of the temperature of the water before and after shaking.
Experimental Record
Temperature
Before Shaking 21 °C
After Shaking Unknown
What best predicts the unknown temperature? (3 points)
Less than 21 °C because heat energy is formed from the energy used in shaking
Greater than 21 °C because heat energy is formed from the energy used in shaking
Less than 21 °C, because the total energy of the system after shaking is higher than before shaking
Greater than 21 °C, because the total energy of the system after shaking is higher than before shaking
9.
(01.04 HC)
The table shows the potential energy and kinetic energy of a skier at two different positions on a hill.
Position and Energy
Position (above ground) Kinetic Energy Potential Energy
100 meters 0 units 50,000 units
60 meters ? 30,000 units
What is the kinetic energy of the skier at a height of 60 meters above ground? (3 points)
20,000 units, because total energy remains unchanged
80,000 units, because total energy remains unchanged
20,000 units, because total energy of the skier decreases
80,000 units, because total energy of the skier decreases
Answer: Greater than 21 °C because heat energy is formed from the energy used in shaking
Explanation: I got this test and i got it right
The temperature of the water will be greater than 21 °C because the shaking converts the kinetic energy into thermal energy. The kinetic energy of the skier at a height of 60 meters is 20,000 units.
Explanation:The law of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. In the experiment described, the shaking of the flask converted the kinetic energy of the students' motions into thermal energy, thereby increasing the temperature of the water. Therefore, the temperature of the water after shaking will be greater than 21 °C because heat energy is formed from the energy used in shaking.
The kinetic energy of the skier can be calculated by subtracting the potential energy at the height of 60 meters from the potential energy at the height of 100 meters. Since the potential energy at the height of 100 meters is 50,000 units and the potential energy at the height of 60 meters is 30,000 units, the difference is 20,000 units. Therefore, the kinetic energy of the skier at a height of 60 meters is 20,000 units.
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Consider a sample of calcium carbonate in the form of a cube measuring 2.805 in. on each edge.
If the sample has a density of 2.70 g/cm3 , how many oxygen atoms does it contain?
To find the number of oxygen atoms in a sample of calcium carbonate, calculate the number of moles of calcium carbonate and multiply by the number of oxygen atoms per molecule. The sample contains approximately 29.331 oxygen atoms.
Explanation:To determine the number of oxygen atoms in a sample of calcium carbonate, we need to know the number of moles of calcium carbonate and the formula of calcium carbonate. The formula for calcium carbonate is CaCO3, which means there is one calcium atom (Ca), one carbon atom (C), and three oxygen atoms (O) in each molecule of calcium carbonate.
First, we need to find the volume of the cube. The volume of a cube is given by V = s3, where s is the length of the sides of the cube. In this case, the length of the sides of the cube is 2.805 in. Therefore, the volume is V = 2.8053 = 22.124 in3.
Next, we need to convert the volume from cubic inches to cubic centimeters, as the density is given in g/cm3. Since 1 in3 = 16.3871 cm3, the volume in cm3 is 22.124 in3 * 16.3871 cm3/in3 = 362.274 cm3.
Finally, we can calculate the mass of the sample of calcium carbonate using the density formula: density = mass/volume. Rearranging the formula, mass = density * volume. Plugging in the values, mass = 2.70 g/cm3 * 362.274 cm3 = 978.780 g.
Now, we know the mass of the sample, which is equal to the molar mass of calcium carbonate multiplied by the number of moles. The molar mass of calcium carbonate (CaCO3) is calculated by adding the atomic masses of calcium, carbon, and three oxygen atoms: 40.08 g/mol + 12.01 g/mol + (3 * 16.00 g/mol) = 100.09 g/mol.
Using the equation: mass = molar mass * moles, we can solve for the moles of calcium carbonate in the sample. Rearranging the equation, moles = mass / molar mass. Plugging in the values, moles = 978.780 g / 100.09 g/mol = 9.777 mol.
Since there are three oxygen atoms in each molecule of calcium carbonate, the total number of oxygen atoms in the sample is calculated by multiplying the number of moles of calcium carbonate by the number of oxygen atoms per molecule: 9.777 mol * 3 = 29.331 oxygen atoms.
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Tim puts his spare change in a jar each day when he comes home. When the jar is full he separates the coins and takes them to the bank. The coins would be classified as a _________.
A) compound
B) element
C) mixture
D) solution
Answer:
C) mixture
Explanation:
Mixture : It is defined as the substance that is made by the combination of two or more different components.
Hence, they can be separated. Answer - C
Pure substance : It is defined as a substance that is made by the combination of only one type of atom or only one type of molecule.
Compound : It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Element : It is a pure substance which is composed of atoms of similar elements.
Solution: It is the special type of the homogeneous mixture which is composed of more than one substances.
How do you draw the Lewis dot structure for CF2Cl2?
Answer:
C in the middle with 2x F and 2x Cl bound to it. Both F and Cl have 7 valence electrons. ( See photo)
Explanation:
Of the three ( C, F and Cl) carbon has the lowest electro negativity so we expect it to be in the middle.
C: 4e-
F: 7e- x 2 = 14e-
Cl: 7e- x2 = 14e-
4+14+14 = 32 electrons : octet rule
CF2CL2 = Dichloro Difluoro Methane,
To draw the Lewis dot structure for CF2Cl2, begin by calculating the total number of valence electrons, arrange the atoms with Carbon in the center, then create bonds and distribute the remaining electrons to observe the octet rule. The final Lewis structure would satisfy the octet rule for all atoms in the molecule.
Explanation:To draw the Lewis dot structure for CF2Cl2, we need to follow certain steps. Firstly, find the total number of valence electrons. Carbon (C) has 4, Fluorine (F) has 7 each, totaling 14 for the pair, and Chlorine (Cl) also has 7 each, totaling 14 as well for both atoms in the compound. This gives us a total of 32 valence electrons. Next, arrange the atoms with Carbon in the middle and fluorine, and Chlorine atoms surrounding it.
Now, draw a single bond between the Carbon and Fluorine atoms, and also the Carbon and Chlorine atoms to signify shared electrons and subtract the shared electrons from the total of 32. Each bond contains two electrons. The remaining 24 electrons should be distributed among the Fluorine and Chlorine atoms to satisfy the octet rule (each atom should have 8 electrons in its outer shell). This means adding three lone pairs to each Fluorine atom and each Chlorine atom.
The final notation would look like CF2Cl2 with each non-carbon atom surrounded by eight electrons, fulfilling the octet rule. The atom in the center, Carbon, also shares eight electrons, therefore, the octet rule is satisfied for every atom in the molecule.
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Convert: 127 degrees Celsius = ______K -400 127 400 146 -146
Answer:
400.15 kelvin
Explanation:
Which undefined geometric term is described as a two-dimensional set of points that has no beginning or end?
Answer:
The two-dimensional set of points that has no beginning or end is described by the undefined geometric term plane.Explanation:
There are three undefined terms in geometry:
point,line, andplaneThey are referred as undefined terms because they are not defined in a formal way, i.e. using mathematically defined words. At the end these terms are abstractions (ideas).
The point has no dimensions, it can be represented by the tip of a sharp pencil.
The line is referred as an infinite set of joined points that extend indefinitely in one direction (from right to left, from north to south), so it has one dimension. The intersection of of two perpendicular walls is an example of what a line is.
Finally, the term to which the question is referred is the plane: an infinite set of joined points that extends in two dimensions. An example of plane is the surface of quite water. The plane does not have depth, only extension; that is why it has only two dimensions.
So, you should remember: points do not have dimensions, lines have one dimension, and planes have two dimensions.
Can you determine which of two unknown elements has the larger radius if the only known information is that the atomic number of one of the elements is 20 greater than the other? Explain.
Answer:
Yes, you can determine which one.
Explanation:
Hi, there are many factors that can be used to compare the atomic radius of to elements but the most important is the amount of electrons each atom has.
The atomic number represents the amount of protons and electrons (if the element isn't ionized) that the atom has.
The more electrons the atom has, the more energy levels it completes. And each of this levels has a longer radius than the one before it.
So, higher levels completed represent longer atomic radius.
In conclusion, a element with an atomic number 20 greater than the other has 20 more electrons, completed more energy levels and its radius will be longer
what are metalloids
A metalloid is an element that has properties that are intermediate between those of metals and nonmetals. Metalloids can also be called semimetals. On the periodic table, the elements colored yellow, which generally border the stair-step line, are considered to be metalloids.
Final answer:
Metalloids are elements with intermediate properties between metals and nonmetals, found along the staircase line of the periodic table and exclude aluminum and polonium. They are semiconductors with applications in electronics, as their conductivity increases with temperature. Silicon is a well-known metalloid, which is used for its semiconductor properties.
Explanation:
Metalloids are elements that exhibit properties intermediate between those of metals and nonmetals. These elements, sometimes referred to as semimetals, are located on the periodic table along a staircase line starting from element 5B (boron) and ending at 85At (astatine), excluding aluminum and polonium which are classified as metals. Metalloids such as boron, silicon, germanium, arsenic, antimony, and tellurium display a combination of metallic and nonmetallic characteristics, for instance, they tend to look metallic, but they do not conduct electricity as well as metals and thus are considered semiconductors.
These elements find numerous applications in the field of electronics due to their unique ability to control electrical conductivity. Their conductivity increases with temperature, a property that distinguishes them from metals and makes them valuable in electronic devices. The intermediate electronegativity and chemical behaviors are due to their electron structure, making them versatile in reactions; they form covalent crystals unlike metals but do not form monatomic anions like nonmetals. Silicon, a prominent metalloid, is particularly noted for its luster and brittleness.
What happens to the temperature of a substance while it is changing state? Explain.
Answer:
the temperature of a substance while changing often times while rise or fall depending on what is happening. Say you have an ice cube and you put it into a hot soup to cool the soup down the ice cube melts due to the surrounding temperature. In other cases if you want to cool something hot like say hot water you can 1:put it in a cool place such as a refrigerator or freezer or 2:you can leave it out to cool to room temperature.
If something I said didnt make sense plz dont get mad or anything I am only in jr.high in 8th grade and the school year is still fresh so I'm trying to catch up on somethings.
Answer:
When any substance changes its state, the temperature remains constant.
Explanation:
It happens so because the amount of heat supplied during the change of state of any substance is utilized to break the intermolecular forces of attraction or other kinds of forces.
Which equation represents the combined gas law?
o Pq Va = P2 V2
| VI VÀ
O TT
Pq Vq Tq = P₂ V 2T 2
Answer:
The answer to your question is below:
Explanation :
The combined gas law as it name says it combines three gas laws: Boyle's law, Charles' law and Gay Lussac Law. It states that at initial conditions of pressure, volume and temperature, it there is a change in one of this variables
the equilibrium will be equivalent to a second equilibria of pressure, volume and temperature.
[tex]\frac{P1V1}{T1} = \frac{P2V2}{T2} \\[/tex]
"1" indicates initial conditions
"2" indicates final conditions
The combined gas law is represented by the equation P1V1/T1 = P2V2/T2 and is used to model the behavior of gases when the number of moles and the ideal gas constant are constant.
The equation that represents the combined gas law is:
P1V1/T1 = P2V2/T2
This law combines Boyle's law, Charles's law, and Gay-Lussac's law, and it is used when the number of moles (n) of a gas and the ideal gas constant (R) are held constant. The combined gas law allows us to predict how a gas will behave under different sets of conditions in terms of pressure (P), volume (V), and temperature (T), assuming the amount of gas in moles does not change.
Examples of Gas Laws:
Boyle's Law: P1V1 = P2V2 (at constant n and T)
Charles's Law: V1/T1 = V2/T2 (at constant n and P)
Gay-Lussac's Law: P1/T1 = P2/T2 (at constant n and V)
Each can be derived from the combined gas law depending on which variables are held constant.
On a caterpillar's map, all distances are marked in millimeters. The caterpillar's map shows that the distance between two milkweed plants is 4, 012milim . What is this distance in kilometers ?
Answer:
0.004012km
Explanation:
Problem:
Conversion of millimeters(mm) to Kilometers:
value given = 4012mm
Here, we are converting from a submultiple unit to a multiple unit.
Millimeter depicts 10⁻³m and kilometer stands for 10³m
Now, we must find how many exponents will take us from 10⁻³ to 10³
careful examination shows that if we multiply a power of 10⁶ to 10⁻³ it will give a 10³:
i.e 10⁻³ x 10⁶ = 10⁻³⁺⁶ = 10³
Therefore,
10⁶mm = 1km
4,012mm = [tex]\frac{4012}{1000000}[/tex] = 0.004012km
To convert millimeters to kilometers, we have to remember that 1 kilometer equals 1000 meters and 1 meter equals 1000 millimeters, hence 1 kilometer equals 1,000,000 millimeters. So, 4012 millimeters is equal to approximately 0.004012 kilometers.
Explanation:
The subject of this question pertains to unit conversion within the metric system. Given a distance measured in millimeters (mm), we want to convert this to kilometers (km). To convert, we will utilize the fact that 1 kilometer equals 1000 meters and 1 meter equals 1000 millimeters. Therefore, 1 kilometer equals 1,000,000 millimeters.
To convert 4012 millimeters into kilometers, we divide 4012 by 1,000,000, which gives us approximately 0.004012 kilometers. So, the distance between the two milkweed plants on the caterpillar's map, when converted to kilometers, is 0.004012 kilometers.
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what are cathode rays made of
Answer:
electrons
Explanation:
they are composed of negatively charged particles also known as electrons
Cathode rays are made up of electrons, which are particles with a negative charge and mass. This was determined through historical experiments that demonstrated cathode rays' deflection by magnetic and electric fields and measured their charge-to-mass ratio.
Explanation:Cathode rays are composed of particles known as electrons. Historical experiments conducted by scientists like J. J. Thomson and William Crookes revealed the nature of these rays. Using a cathode ray tube, Crookes observed that a paddle wheel placed between the electrodes moved from the cathode towards the anode upon the commencement of the tube, suggesting that the rays had mass. Similarly, Thomson's experiments, which involved deflecting the cathode ray with magnetic and electric fields, established that these rays are indeed made up of charged particles with a negative charge and have a specific mass-to-charge ratio.
The discovery that cathode rays are deflected away from a negatively charged electrical field and toward a positively charged field, along with their response to magnetic fields, was crucial in determining their particle nature. Thomson's calculation of the electron's charge-to-mass ratio further cemented the understanding of cathode rays, leading to the realization that electrons are fundamental components of all atoms, not just specific types of gases or metals used in the experiments.
How many calories would be needed to heat 5.0 lbs of copper from 22 degrees C to 80.0 degrees C? C for copper = 0.092
Answer:
[tex]1.21\times 10^4[/tex] cal would be needed to heat 5.0 lbs of copper from 22 degrees C to 80.0 degrees C.
Explanation:
[tex]Q=m \times c \times \Delta T[/tex]
where
[tex]\Delta T[/tex] = Final T - Initial T
Q is the heat energy in calories
c is the specific heat capacity (for copper 0.092 cal/(g℃))
m is the mass of water
plugging in the values
[tex]$Q=5.01 b s \times 0.092 \frac{c a l}{g^{\circ} \mathrm{c}} \times\left(80.0^{\circ} \mathrm{C}-22^{\circ} \mathrm{C}\right)$[/tex]
Please Note:
1 lb = 453.592grams
So,
5 lbs = 5 × 453.592g = 2268 g
[tex]$\begin{aligned} Q &=2268 g \times 0.092 \frac{c a l}{g^{\circ} \mathrm{C}} \times 58^{\circ} \mathrm{C} \\\\ Q &=12102 \mathrm{cal} \end{aligned}$[/tex]
[tex]=1.21\times10^4[/tex] cal (Answer)
In pea plants, yellow seed color is completely dominant to green seed color.
A pure yellow-seeded plant is crossed with a pure green-seeded plant. What
alleles will be present in the body cells of the offspring?
Answer:
Assuming that the Alleles are uppercase Y for the dominant yellow and lowercase y for the recessive green, the alleles present in the hybrid plant will be Yy, and the color would be yellow as it is a dominant trait.
Answer:
We need to use a Punnett Square to figure this out.
Explanation:
Let's say that for the pea plants, Big Y represents the color yellow while Little y is the color green. If Big Y is dominant (which determines the plant's color) it means the plant is yellow. If Little y is dominant, the plant is green.
A phenotype (the genetic makeup of the offspring) would be green if it's genotype was Yy , or YY. It would be yellow if it was yy.
Both "parent" plant's genotype is "pure" which I'd presume means homozygous (two big letters). We need to use a mono-hybrid cross (4 squares, 1 trait) and cross the parents to see what we get.
MOM PEA PLANT - yy (green, homozygous recessive)
DAD PEA PLANT - YY (yellow, homozygous dominant)
OFFSPRING - 100% Yy (yellow, heterozygous)
There is no way that the parents could make a green plant with their genotypes. So the probability is that 100% of their offspring would be yellow, with the phenotype Yy.
Boron - 10 emits alpha particles and cesium - 137 emits beta particles. Write balanced nuclear
reactions for each radioactive decay.
The balanced nuclear reaction is:10/5 B → 4/2 He + 6/3 Li.The balanced nuclear reaction is:137/55 Cs → 137/56 Ba + 0/-1 e Where Ba stands for Barium.
The balanced nuclear reaction for Boron-10 emits alpha particles and cesium-137 emits beta particles are as follows:Balanced nuclear reaction for Boron-10:Boron-10 emits an alpha particle, which consists of two protons and two neutrons, therefore the atomic mass of Boron-10 decreases by four, and the atomic number decreases by two, resulting in the formation of a new atom i.e. Helium-4.
Balanced nuclear reaction for Cesium-137:Cesium-137 emits a beta particle which is an electron, and when a beta particle is emitted, a neutron inside the atom changes into a proton, resulting in the formation of a new atom with the same mass number, but an atomic number that has increased by one.
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Final answer:
The radioactive decay of Boron-12 by beta particle emission can be represented by the nuclear equation ⁵B¹² → ⁵C¹² + ⁰e⁻ + γ, resulting in Carbon-12 and a gamma ray. For Cesium-137, the decay is represented by ⁵⁵Cs¹³⁷ → ⁵⁶Ba¹³⁷ + ⁰e⁻, producing Barium-137 and a beta particle.
Explanation:
The student's question requires writing balanced nuclear equations for the radioactive decay of Boron-10 and Cesium-137. However, the question has an error since Boron-10 does not usually emit alpha particles, so we will correct it to Boron-12, which undergoes beta decay:
Boron-12 emitting a beta particle and a gamma ray can be represented as:
⁵B¹² → ⁵C¹² + ⁰e⁻ + γ
In this equation, Boron-12 ( ⁵B¹² ) decays to Carbon-12 ( ⁵C¹² ) by emitting a beta particle (⁰e⁻) and a gamma ray (γ). The gamma ray represents the release of excess energy after the decay.
For Cesium-137 undergoing beta decay, the equation is as follows:
⁵⁵Cs¹³⁷ → ⁵⁶Ba¹³⁷ + ⁰e⁻
In this equation, Cesium-137 (⁵⁵Cs¹³⁷) decays to Barium-137 (⁵⁶Ba¹³⁷) by emitting a beta particle (⁰e⁻).
Which best describes ionization energy ?
Answer:
Ionization energy is the energy needed to remove an electron from an atom or ion in a gas phase.
HOPE THIS HELPED!!!!!!!!!!!!!! XDDDDDDD
Answer:
Are there multiple choices if they're is please show them for example
A.Apple
B.Banana
C.Carrot
D.Plums
What is the de Broglie wavelength of an electron traveling at 1.62×105 m/s ?
Answer:
0.449 10^(-8) meters
[tex]0.449 * 10^{-8}[/tex] meters
Explanation:
Use the deBroglie equation for the wavelength (lambda):
[tex]lambda = \frac{h}{m*v}[/tex]
where h stands for the Plank constant: [tex]6.6261 * 10^{-34} J[/tex]
m stands for the mass of the electron: [tex]9.109 * 10^{-31} kg[/tex]
and v is the given velocity: [tex]v = 1.62 * 10^5 \frac{m}{s}[/tex]
Evaluating lambda for these values:
[tex]lambda = \frac{h}{m*v}= \frac{6.6261 * 10^{-34} }{9.109 * 10^{-31} * 1.62 * 10^{5}} = 0.449* 10^{-8} m[/tex]
Answer : The wavelength of an electron is, [tex]4.39\times 10^{-9}m[/tex]
Explanation :
According to de-Broglie, the expression for wavelength is,
[tex]\lambda=\frac{h}{p}[/tex]
and,
[tex]p=mv[/tex]
where,
p = momentum, m = mass, v = velocity
So, the formula will be:
[tex]\lambda=\frac{h}{mv}[/tex]
where,
h = Planck's constant = [tex]6.626\times 10^{-34}Js[/tex]
[tex]\lambda[/tex] = wavelength = ?
m = mass of electron = [tex]9.31\times 10^{-31}kg[/tex]
v = velocity = [tex]1.62\times 10^5m/s[/tex]
Now we have to calculate the wavelength.
Now put all the given values in the above formula, we get:
[tex]\lambda=\frac{h}{mv}[/tex]
[tex]\lambda=\frac{6.626\times 10^{-34}Js}{(9.31\times 10^{-31}kg)\times (1.62\times 10^5m/s)}[/tex]
[tex]\lambda=4.39\times 10^{-9}m[/tex]
Therefore, the wavelength of an electron is, [tex]4.39\times 10^{-9}m[/tex]
A sample of gas is enclosed in a container of fixed volume, Identify which of the following statements are
true. Check all that apply.
If the container is heated the gas particles will lose kinetic energy and temperature will increase.
If the container is cooled, the gas particles will lose kinetic energy and temperature will decrease.
If the gas particles move more quickly, they will collide more frequently with the walls of the container
and pressure will increase.
If the gas particles move more quickly, they will lose energy more rapidly and collide with the walls of
the container less often, and pressure will decrease.
If the gas particles move more quickly, they will collide with the walls of the container more often and
with more force, and pressure will increase.
Answer:
If the container is cooled, the gas particles will lose kinetic energy and temperature will decrease.
If the gas particles move more quickly, they will collide more frequently with the walls of the container and pressure will increase.
If the gas particles move more quickly, they will collide with the walls of the container more often and with more force, and pressure will increase.
Explanation:
The temperature of gases is a measure of the average kinetic energy of the molecules. With increasing temperature comes more kinetic energy for the gaseous particles. If temperature of the system is reduced, the particles will have less kinetic energy and would not be able to move. Temperature is directly proportional to average kinetic energy.
Pressure of gases increases when there is more frequent collision between their particles. The usual case is for gases to move more rapidly as a result of increase in kinetic energy of the system. The particles collides more frequently with one another and the walls of the container if the kinetic energy is raised.
Answer:
If the container is cooled, the gas particles will lose kinetic energy and temperature will decrease.
If the gas particles move more quickly, they will collide more frequently with the walls of the container and pressure will increase.
If the gas particles move more quickly, they will collide with the walls of the container more often and with more force, and pressure will increase.
Explanation:
calculate the concentration of OH- of a solution of hydrobromic acid (HBr) given that its pH is 1.7
Answer:
Explanation: This is Quite matching Answer. The formula for pH is pH = -log[H+]. This means pH is the negative base 10 logarithm ("log" on a calculator) of the hydrogen ion concentration of a solution. To calculate it, take the log of the hydrogen ion concentration and reverse the sign to get the answer.
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Experiment #2
Question: Do different types of music affect how well a person can do his/her homework?
Hypothesis: Music that does not have a strong beat makes concentrating on a homework assignment easier.
Music with heavy beats makes concentration more difficult.
Experiment:
Sara Lilia pulled out four different CD's to find out which type helped her to finish her homework the
fastest. The first CD was rock, the second reggaeton, the third classical, and the fourth was cumbia. She chose a
math assignment that required concentration.
Sara Lilia used a stopwatch with an alarm to make sure that she only listened to each CD for 5 minutes.
Each time the alarm went off, Sara Lilia recorded how many problems she was able to finish.
At the end of the experiment, she found that she was able to concentrate the most with the classical
music, then the rock, and the cumbia. She noticed that she did not concentrate much at all with the reggaeton
and felt like dancing and singing along instead of working.
A. What was the independent variable?
B. What was the dependent variable?
C. What was the control?_
D. Was there a constant variable?
Answer:
Explanation:
An independent variable is a variable in which does not rely on how other variables. It is usually cause in an experiment. From Sara Lilia experiment, we can identify the different music genres as her independent variable.
The dependent variable here is her ability to concentrate in her study. Here, we should know that the dependent variable is often the result of the effects of the independent variable.
There is no control in the experiment. In the controlled set up, we would have put all other know factors that would make concentrations easier into consideration. It could be the environment, the arrangement of the room and a particular time of the day. None of such was stated in the experiment.
The constant variable is the variable that was held fixed throughout the experimental procedure. Here the time of study was fixed at 5minutes. What would happen to concentration if this time was shorter or much more?
The chemical formula of a compound does not indicate?
Answer: Option (c) is the correct answer.
Explanation:
A compound is defined as the substance in which different elements are chemically combined together in a fixed ratio by mass.
For example, [tex]MgSO_{4}[/tex] is a compound and elements are present in 1:4 ratio.
A compound can be divided into its constituent or simpler substances.
Hence, a chemical formula shows the elements involved in it along with their identity and relative proportion.
But a chemical formula does not tell how atoms are joined together as it can be done by structural formula and not by chemical formula.
Thus, we can conclude that the chemical formula of a compound does not indicate how elements are joined in the compound.
WHAT HAPPENS TO HOT AIR?
Answer:
Hot air rises
Explanation:
Hot air rises because when you heat air (or any other gas for that matter), it expands. When the air expands, it becomes less dense than the air around it. The less dense hot air then floats in the more dense cold air much like wood floats on water because wood is less dense than water.
Write a balanced chemical equation for the decomposition of RbNO3.
Help me please!!!
Answer:
2RbNO³ --> 2Rb + N² + 30²
Hope this helps!
The decomposition of RbNO3 can result in different products depending on the reaction conditions, and alkali metal nitrates typically decompose into their metal oxides, nitrogen dioxide, and oxygen. For an accurate balanced equation, specific details regarding the decomposition conditions are necessary.
Explanation:The decomposition of RbNO3 (rubidium nitrate) would lead to the formation of rubidium nitrite (RbNO2) and oxygen (O2). However, typical nitrates of alkali metals like rubidium do not decompose into nitrites and oxygen as do nitrates of heavier metals; instead, they usually decompose into the nitrate's corresponding metal oxide, nitrogen dioxide, and oxygen. Therefore, since this behavior can be complex and context-dependent, I would need more specific information about the conditions of the decomposition to provide a precise equation.
Let's take a more generic example for illustrative purposes:
Decomposition of potassium chlorate: 2 KClO3 → 3 O2 + 2 KCl.In case of RbNO3, if we were to speculate a similar simple decomposition, a balanced chemical equation might be:
2 RbNO3 → 2 RbNO2 + O2.
However, this is just a hypothetical example and should not be taken as the actual decomposition of rubidium nitrate. Understanding the decomposition of such compounds requires knowledge of the specific conditions under which the reaction occurs.
Select the correct answer.
An ion has a net charge of 3+. If this ion has 8 protons, how many electrons does it have?
Answer 12
Explanation:
Answer:
Ion formed from the atom contains 8 positive protons and 5 negative electrons
Explanation:
Atomic number = number of electrons = number of protons
So the atom contains 8 protons and 8 electrons
Protons are positively charged and electrons are negatively charged.
An ion with a positive charge (cation) is formed by the loss of negative electrons
An ion with a negative charge (anion) is formed by the gain of negative electrons.
The question says ion has a net charge of 3+ so it means the atom has lost 3 electrons from it.
So ion formed from the atom contains 8 positive protons and 5 negative electrons (Answer)
To find the number of neutrons we make use of the formula
Please Note: Mass number - atomic number = number of neutrons
The ratio of the mass of O to the mass of N in N2O3 is 12:7. Another binary compound of nitrogen has a ratio of O to N of 16:7.
What is its formula?
Express your answer as a chemical formula.
Answer:
NO2
Explanation:
Molar mass of Nitrogen (N) is 14g/ mole . Molar mass of O is 16g/ mol. So the ratio of atoms of each is :
Moles of O = mass of O / Molar mass O = 12 / 16 = 0.75 = 3/4 mole of O
Moles of N = mass of N / Molar mass N = 7 / 14 = 0.5 = 1/2 mole of N
So to scale these fractions to a whole number, multiply both by 4.
4 x 3/4 = 3 moles of O; 4 x 1/2 = 2 moles of N. This confirms your first answer: N2O3.
Do the same for the ratio 16:7.
Moles O: 16 / 16 = 1 mole of O
Moles of N: 7 / 14 = 1/2 mole of N
This means for each 1/2 mole of N we have 1 mole of O; or for each mole of N we have 2 moles of O : the ratio is 2.
Multiplying both by 2: N = 1 mole; O = 2 moles. So the molecule is NO2.
Consider the reaction of methane with ammonia and oxygen.
2CH4 (g) + 2NH3 (g) + 3O2 (g) 2HCN (g) + 6H2O (l)
Determine the limiting reactant in a mixture containing 123 g of CH4, 114 g of NH3, and 423 g of O2. Calculate the maximum mass (in grams) of hydrogen cyanide, HCN, that can be produced in the reaction.
The limiting reactant is:
NH3
CH4
O2
Amount of HCN formed =
g
The limiting reactant in the reaction is NH3. The maximum mass of HCN that can be produced is approximately 180.63 g.
Explanation:To find the limiting reactant, you firstly convert the mass of each reactant to moles. For CH4, the molecular weight is approximately 16.04 g/mol, so 123 g CH4 is 123/16.04 = about 7.67 moles. For NH3, the molecular weight is approximately 17.03 g/mol, so 114 g NH3 is 114/17.03 = about 6.69 moles. For O2, the molecular weight is approximately 32 g/mol, so 423 g O2 is 423/32 = about 13.22 moles.
The balanced equation shows that the reaction consumes CH4, NH3 and O2 in a 2:2:3 ratio. So for the given amount of reactants, the number of mole ratios is 7.67/2 = 3.84 for CH4, 6.69/2 = 3.35 for NH3 and 13.22/3 = 4.41 for O2. The smallest value is NH3’s which is 3.35, so NH3 is the limiting reactant.
The balanced equation shows that 2 moles of NH3 will produce 2 moles of HCN. Therefore, 6.69 moles of NH3 will produce 6.69 moles of HCN. As the molar mass of HCN is 27 g/mol, the maximum mass is 6.69 moles * 27 g/mol = approximately 181.63 g of HCN.
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which of the following is an example of inference? Explain WHY.
A. The girl is wearing red shoes
B. My science binder has 45 pages in it.
C. Ms. Sparks must be a great reader she is always carrying around books.
D. There is a cat sitting by the window.
Answer:
C
Explanation:
This is because you are guessing that since Mrs. Sparks always carries around books, she must be a great reader. All the other answers are just facts that you see. For c, you are guessing this.
Answer:
C
Explanation:
Must is the key word. An inference is a guess, you guess Ms. Sparks must be a great reader because she is always carrying around books. You don't know for sure she is a great reader which makes it an inference. Hope this helps!
What does it mean if Gram-negative bacteria are found in the sample? Why would they be present in the sample?
Answer:
See explanation
Explanation:
In yogurt are usually found, (several ) types of gram- positive bacteria. Those bacterias are used to made yogurt, and don't bring negative effects on the human body. These bacterias are Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus bacteria.
When doing a gram-staining on a yogurt sample, this staining will show a positive result if there are gram- positive bacteria present, what is most likely to happen.
In a yogurt sample, normally, no gram-negative bacteria will occur. Although, if gram - negative bacteria will be found. This means the yogurt sample is infected. Those bacteria are (probably) diarrhea causing bacteria such as E. coli and Salmonella.
If gram-negative bacteria are found in the sample, the gram-staining will be negative and show red/pink bacteria.
how to convert moles to molecules
Explanation:
To convert from moles to molecules we simply multiply the number of moles by Avagadro's number, 6.02 × 10²³.
For example if we have 1 mol of a substance we have 6.02 × 10²³ molecules of that substance.
1 mol × 6.02 × 10²³ = 6.02 × 10²³ molecules.
To convert moles to molecules, multiply the number of moles by Avogadro's number, which is 6.022 x 10²³ molecules/mole.
To convert moles to molecules, you need to use Avogadro's number. Avogadro's number is 6.022 x 10²³, which is the number of molecules (or atoms, ions) in one mole of a substance.
Here are the steps for the conversion:
First, identify the number of moles you want to convert.
Next, multiply the number of moles by Avogadro's number (6.022 x 10²³ molecules/mole).
For example, if you have 2 moles of a substance, the number of molecules is calculated as follows:
Molecules = Moles x Avogadro's number
Molecules = 2 moles x 6.022 x 10²³ molecules/mole
Molecules = 1.2044 x 10²⁴ molecules
So, 2 moles of a substance contain 1.2044 x 10²⁴ molecules.
If a light ray strikes a flat mirror at an angle of 27 degrees, what will the reflected ray be?
30 degrees from the mirror's surface
pretty sure It's correct and if it is then your welcome
The concept law of reflection is used here to find out the angle of reflected ray. The angle of reflected ray is also 27 degree. The light reflected from a mirror surface is an example of reflection of light.
What is Law of reflection?The law of reflection states that the angle of reflection is always equal to the angle of incidence. Here the incident ray, reflected ray and the normal to the surface of the mirror is found to lie in the same plane.
A common reflected image is given by the the law of reflection where the distance between the object and the mirror is same as that of the distance between the image and the mirror.
The law of reflection can be shown here.
Thus the angle of reflected ray is 27 degree which is same as that of incident angle.
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