Rubidium's atomic number is 37.
Hope this helps!
Answer:
Atomic number 37!
Explanation:
pls help me I need this answer ______ are easier to work with than reality and can be manipulated. Computers Observations Experiments Models
it is not observations
Answer:
Models
Explanation:
Models are abstractions of the real world. Models helps to mimick what is actually the true representation of a body. It is easier to work with models because they are our own creation. This makes them flexible to carryout any form of adjustments and manipulations. We can try out a model with different variables to simulate an obtainable result.
Models are easier to work with than the complex reality with a lot of factors and conditions that may not be easily predictable and under control.
which organism does not have a tail or black hair
One mole of liquid water is in a closed vessel whose temperature is 273 K, whose initial internal pressure is 1 atm (the space above the liquid is filled with air), and whose interior volume is 50 times the volume of the water. Calculate the volume of the vessel. Now the vessel is heated to the boiling point of water. Assuming that the gases are ideal, calculate the pressure in the vessel.
Answer:
1) volume of the vessel = 22.86 L
2) the pressure in the vessel = 1.37 atm
Explanation:
to Calculate the volume of the vessel we are going to use this formula :
PV = nRT
when :
P is a pressure which is the force per unit area extended by the gas on the vessel = 1 atm
V is a volume which is the amount of space occupied by air or gas= ??
n is the number of moles = 1 mole
R is the ideal gas constant = 0.08206 L atm mol-1K-1
T is temperature in kelvin =273 K
by substitution:
1 atm * V = 1* 0.08206 * 273
V of air = 22.4 L
to assume V of water we can make this equation:
volume of the vessel = V of water + V of air
by Assuming V of water = X & volume of the vessel = 50 X
so ,
50 X = X + 22.4 L
X = 22.4 L/49 = 0.457 L
so,volume of the vessel = 0.457 *50 or ( 0.457+22.4) = 22.86 L
2) to calculate the pressure in the vessel at constant volume:
P1/T1 = P2/T2
at constant volume the relation between pressure and temperature is directly proportional
when the boiling point of water is equal = 100 °C = 100 + 273 = 373 K
1 atm /273 K = P2 / 373K
So P2 = 373/273*1
= 1.37 atm
Both protons and neutrons are located inside the nucleus of an atom. Changing the number of neutrons in the nucleus would form different isotopes of the same element. Which of these BEST describes the outcome of decreasing the number of protons in the nucleus?
A) The element would become an ion.
B) The atom would become a different element.
C) The number of neutrons would also decrease.
D) The atomic mass of the element would increase.
Answer:
A
Explanation: Decreasing the protons makes the atom negatively charged as there is less protons and more electrons therefore it's an ion now.
Answer:
B) The atom would become a different element.
Explanation:
As we know, the proton is a subatomic particle characterized as the particle that has a positive charge.
An atom can gain, lose or share electrons to achieve electronic stability. However, this does not happen with the proton. If the number of protons in a element decreases, that element begins to have a different atomic number, which indicates that another element has been formed.
You and your roommates have already decided to spend a week volunteering in the relief effort over the winter break, but in order to convince your roommates to write to Congress to demand action on climate change, you want to give them a sense of how much water fell. To do this, you calculate how many gallons of water would be in your dorm room if 52 inches of rain landed in this space. Assume that your dorm room is 228 ft^2 and know that 1 gallon = 231 in^3 and that 1 foot = 12 inches.
Answer:
Gallons of water in the dorm room =7391 gallons
Explanation:
Given:
Amount of rainfall = 52 inches
Area of the room = 228 ft^2
To determine:
The gallons of water in the room
Calculation:
Convert area of room from ft^2 to inches^2
1 foot = 12 inches
Therefore, [tex]1 ft^{2} = (12\ in)^{2} = 144\ in^{2}[/tex]
Area of room is:
[tex]\frac{228ft^{2}*144in^{2}}{1ft^{2} } =32832in^{2}[/tex]
Volume of water in the room is:
[tex]=Area\ of\ room * Amount\ of\ rainfall\\\\= 32832 in^{2} * 52\ in = 1707264\ in^{3}[/tex]
Convert from in^3 to gallons:
1 gallon = 231 in^3
Therefore:
[tex]\frac{1707264in^{3} * 1 gallon}{231in^{3}} =7391 gallons[/tex]
Dimensional Analysis: How many days will it take to earn $160 if your pay is $4.00 per hour?
(assume 8 hour work days)
Find the total number of hours needed by dividing the total amount earned by the amount per hour:
160 / 4 = 40 hours
Divide the total number of hours by hours for 1 day:
40 / 8 = 5
It will take 5 days.
3 days
Explanation:
4 dollars a hour
8 hours a day
total 160
4*24=160
24÷8=3
[3]
A student calculates the density of iron as 6.8 g/cm3 using lab data for mass and volume. A handbook reveals that the correct value is 7.39 g/cm3. What is the percent error?
Answer:
7.983761 %
Explanation:
Step 1: What is percent error ?
⇒Percent error is calculated using the following formula:
⇒% error = | Experimental value-theoretical value/theoretical value | x 100%
⇔ this can be written as well as : error = (| Experimental value/ theoretical value | - | Theoretical value / Theoretical value | ) * 100%
⇒ which, after simplifying, will become :
%error = (| Experimental value - theoretical value - 1 |) x 100%
For this case, this means :
%error = ( |6.8 g/cm³ - 7.39g/cm³ - 1 | ) x100%
%error = | 0.92016238 -1 | x100%
%error = |-0.07983761 | x100%
%error = 0.07983761 x100%
%error = 7.983761 %
The %error is 7.983761 %
‘By using displacement reactions it is possible to deduce the order of reactivity of the halogens.’
Discuss this statement with reference to the elements bromine, iodine and chlorine only.
Answer:
Explanation:
The halogens have seven electrons in their outermost shell. Each halogen atom lacks a single electron to make their octet a complete one. Elements in the halogen group are univalent and also acceptors of electrons. They are all non-metals and oxidizing agents. The oxidizing power of the halogens decreases from top to down the group. This is why the more powerful halogens displaces a less powerful one from simple salts.
Cl₂ + 2KBr → 2KCl + Br₂
Cl₂ + 2KI → 2KCl + I₂
Br₂ + 2KI → 2KBr + I₂
I₂ + 2KCl → No reaction
Final answer:
By using displacement reactions, we can deduce the reactivity order of halogens. A more reactive halogen displaces a less reactive one in compounds, and the reactivity order is [tex]F2 > Cl2 > Br2 > I2,[/tex] indicating chlorine is more reactive than both bromine and iodine.
Explanation:
Displacement reactions among halogens indeed allow us to determine their order of reactivity. When a more reactive halogen, like chlorine, reacts with the salt of a less reactive halogen, such as iodide, it displaces the less reactive halogen from its compound. The order of reactivity for halogens is fluorine, chlorine, bromine, and then iodine, with fluorine being the most reactive and iodine being the least. The reaction between chlorine and potassium iodide, which results in the displacement of iodine, can be written as:
[tex]Cl2 (g) + 2KI (aq) -- > 2KCl (aq) + I2 (s)[/tex]
In this reaction, chlorine oxidizes the iodide ions to elemental iodine and is itself reduced. This shows that chlorine is more reactive than iodine. Similar displacement reactions can be set up to compare the reactivity of bromine and iodine or chlorine and bromine, following the principle that a more reactive halogen will displace a less reactive halogen from its compounds.
Who discovered the electron and what instrument did he use?
Answer:J.J. Thomson, he was using a high-vacuum cathode-ray tube
Explanation:(I Googled it)
J.J. Thomson discovered the electron in 1897 using a cathode ray tube.
The discovery of the electron is attributed to the English physicist J.J. Thomson in 1897 through his groundbreaking work with the cathode ray tube. A cathode ray tube operates by passing an electric current through gases at low pressure, forming a glowing beam or cathode ray from the negatively charged cathode to the positively charged anode. Thomson's experiments demonstrated that these rays consisted of negatively charged particles, later named electrons, indicating that atoms were not indivisible as previously thought but composed of smaller subatomic particles. This realization marked a pivotal moment in the understanding of atomic structure, disproving the notion that the atom was the smallest unit of matter.
What is the pH of a solution when the [OH - ] = 1 x 10 -3
Answer:
The pH is 11
Explanation:
Because pH + pOH = 14
and pOH = - log [OH⁻] = - log (1 x 10⁻³) = 3
we can now calculate pH by manipulating equation one above
pH = 14 - pOH = 14 - 3 = 11
Thus the pH of the solution is 11
Which statement about oxidation and reduction in a voltaic cell is true? A. Both oxidation and reduction occur at the anode. B. Both oxidation and reduction occur at the cathode. C. Oxidation occurs at the anode and reduction occurs at the cathode. D. Oxidation occurs at the cathode and reduction occurs at the anode.
Answer:
C. Oxidation occurs at the anode and reduction occurs at the cathode.
Choice number third is the correct option for the given question
Explanation:
Copper and silver nitrate are the two components that form a voltaic cell. These are the two main ingredients which make the Redox reaction possible. The dog reaction that is taking place result in development of charge.
Since copper here is the anode in the reaction oxidation happens here by the solution[tex]AgNO_3[/tex] is cathode this is where reduction takes place.
What is the density of an object if it’s mass is 15 g and it’s volume is 3cm3
Final answer:
The density of an object with a mass of 15 grams and a volume of 3 cm³ is 5 grams per cubic centimeter (5 g/cm³).
Explanation:
The density of an object is calculated by dividing its mass by its volume. In this case, the mass of the object is given as 15 grams and the volume is 3 cm³. The formula for calculating density is:
Density = Mass / Volume
Applying the values provided:
Density = 15 g / 3 cm³ = 5 g/cm³
Therefore, the density of the object is 5 grams per cubic centimeter (5 g/cm³).
A phase diagram shows phase changes of a substance by illustrating which of the following?
Answer:
D) Pressure vs. temperature
Explanation:
A phase diagram is a graph that shows the physical states of a substance under different conditions of temperature and pressure.
For example, the phase diagram below shows the different combinations of temperature and pressure under which water can exist as a solid, a liquid, or a gas.
b. Write the formula for density.
Density is mass divided by volume
Happy to help! Please mark me as the brainliest!
Answer and Explanation:
[tex]\huge\boxed{Density=\frac{mass}{volume}}[/tex]
That's the formula ↑
For a 20-gram mass that takes up a volume of 5 cubic centimeters:
[tex]density[/tex] [tex]is=\frac{20}{5} gm/cm^{3}[/tex]
[tex]=4gm/cm^3[/tex]
A substance contains an arrangement of different types of atoms joined together by chemical bonds. Which of the following classes of substances could this describe?
A) all matter
B) all elements
C) all compounds
D) all pure substances
Answer:
The correct classification of the statement is all compounds.
Explanation:
All matter is defined as something that entirely has weight and occupies some sought of space. That's why it can't be used to describe the above statement.All elements are defined as substances that have an equal number of protons. The atoms in an element contain an exact atomic number.All compounds can be defined as a formation that takes place when a variety of atoms are chemically combined. Hence, this explains the answer above.All pure substances mean that the substance is not mixed with anything at all. It's just by itself.The graph shows the heating curve of a chemical substance as it undergoes state changes from solid to liquid to gas. Analyze the curve, and answer the questions
The substance is entirely solid between positions
B and C
Particles of the substance are in the liquid state and are gaining kinetic energy between positions
Reset
Next
Answer:
Particles of the substance are in liquid state will gain kinetic energy between positions C and D.
Explanation:
Problem it tells us that between B an C the substance is solid, but I would say that is solid between A and B while between B and C it is a melting process in which particles will gain energy to transform from solid to liquid.
Now between C and D the particles of the liquid will receive energy which is transformed in kinetic energy so the participles will move faster.
Between D and E the particles the energy received is spent by the particles to pass from liquid state to vapors state.
What is the energy of a microwave photon of frequency 2.5x 10^9 HZ?
Answer in units of J.
Answer:
the energy of a microwave photon E = 16.565 x 10^-25 Joule
Explanation:
To get the energy of the photon we are going to use this formula : E = hf
when E is the energy of the photon which we need to calculate
h is Planck's constant = 6.626 x 10^-34 J.S
f is the photon of frequency = 2.5 X 10^9 Hz
so by substitution:
the energy of a microwave photon E = 6.626 x 10^-34 J.S * 2.5 X 10^9 S-1
= 16.565 x 10^-25 Joule
Final answer:
The energy of a microwave photon with a frequency of 2.5 x 10⁹ Hz is 1.6565 x 10⁻²⁴ Joules, calculated using Planck's equation.
Explanation:
The question asks: What is the energy of a microwave photon of frequency 2.5 x 10⁹ Hz? To find this energy, we use Planck's equation, which states that the energy (E) of a photon is equal to the product of Planck's constant (h) and the frequency (f) of the photon. Mathematically, this is expressed as E = hf. Planck's constant is 6.626 x 10⁻³⁴ J-s. Substituting the given frequency and Planck's constant into the equation gives E = (6.626 x 10-⁻³⁴J-s)(2.5 x 10⁹ Hz), which calculates to 1.6565 x 10⁻²⁴ Joules (J).
how do chemist define the radius of an atom?
Answer:
" atomic radius is the measure of size of an atom from its center to its boundary of outer most shell "
Explanation:
Atomic radius is the distance from the center of nucleus to the point where the electronic density is maximum.
Types of Atomic Radii :
Atomic radii are divided into three types:
1= Metallic radius
2= Covalent radius
3= Vander Waals radius.
Metallic radius:
Metallic radius is the half of the inter nuclear distance of two adjacent ions in metallic lattice. The valance electrons are free to move in metallic lattice therefore they are weakly attracted by ions of metals.
The metallic radius is always greater than covalent radius because in in covalent bond electrons are strongly attracted between the nuclei of atoms fro example, the covalents radius of Na2 and potassium is 154 and 203 pm respectively while the metallic radius is 186 and 231 pm respectively.
Covalent Radius:
It is the one half distance between the two covalently bonded nuclei of atoms of same element in a molecule.
Van der Waals Radius:
It is one half distance between two adjacent atoms belonging to the two neighbor molecules of element in solid state. Its magnitude is depend upon the packing of atoms in the solid state.
For example Van der Waals radius of chlorine atom is 180 pm.
Periodic trend of atomic radius:
In period:
The Van der Waals and covalent radii decreases in the period from left to right with increase of atomic number. All alkali metals in the left of periodic table have largest size.
In Group:
The atomic radii increases from top to bottom with increase of atomic number.
Final answer:
The atomic radius is defined as half the distance between the nuclei of two identical atoms in a bond; commonly cited types include Van der Waals, ionic, and covalent radii.
Explanation:
Chemists define the atomic radius of an element as the mean or typical distance from the center of the nucleus to the boundary of the surrounding electron cloud. This boundary is not well-defined as electrons exist in probability density functions, making the exact edge of the atom difficult to pinpoint. The commonly used definitions include the Van der Waals radius, the ionic radius, and the covalent radius.
The covalent radius, often used in a practical sense, is half the distance between the nuclei of two identical atoms bonded covalently. The internuclear distance within molecules, which can be measured accurately, helps in determining these radii. For example, the covalent radius of chlorine is taken to be half the distance between two chlorine nuclei in a diatomic Cl2 molecule, which amounts to 99 pm.
rewrite using a single exponent
5(4) • 5(3)
Answer:
the answer is 5⁷
Explanation:
it is 5 to the power of 7 because 5 is it base and then the 4 and 5 get added to get ur exponent
How is energy involved in chemical and physical changes?
Energy is involved in both chemical and physical changes. Chemical reactions involve a change in the bonds of the reactants and can either absorb or release energy. Phase changes also involve energy changes.
Explanation:All chemical reactions involve energy. Energy is a property of matter that is defined as the ability to do work. Chemical reactions can either absorb or release energy. Phase changes, such as solid to liquid or liquid to gas, involve changes in energy. For example, when solid dry ice vaporizes, energy is absorbed. When liquid water becomes ice, energy is released. During chemical reactions, the bonds in the reactants are broken and new bonds in the products are formed, resulting in a change in the amount of potential energy in the reaction.
9474 millimeters to centimeters using scientific notation showing work
Answer:
9.474 x 10^2
Explanation:
ok. first you have to get the value in the required unit so 9474mm/(10mm/cm) = 947.4 so scientific notation states that the number must be raised to any power of an integer and the value of the number being raised must be less than than 10 and more than or equal to 1
so it must have one digit in front so.. 947.4 becomes 9.474 and because you move 2 places to the left, ur power is positive 2
and proof 10^2 is 100 so multiply 9.474 by 100 and u will get 947.4 cm which is also 9474 mm
How many grams are equivalent to 1.80 x 10^-4 tons? (English tons)
Answer:
163.44 g
Explanation:
We know that one ton is equal to 2000 lbs and one lb is equal to 454 grams.
Solution:
1.80 × 10∧-4 ton× 2000 lb/ton× 454 g/lb
1.80 × 10∧-4 ton× 2× 10³lb/ton× 454 g/lb
1634.4 g/ 10 = 163.44 g
Final answer:
To convert 1.80 x 10^-4 tons into grams, multiply by 2,000 to get pounds, and then by 453.59237 to convert pounds to grams, resulting in 81.646826 grams.
Explanation:
To convert 1.80 x 10^-4 tons to grams, you'll need to multiply the number of tons by the unit equivalence. In the English or Imperial system, 1 ton is equivalent to 2,000 pounds, and we know that 1 pound is equal to 453.59237 grams. Therefore, the calculation to convert tons to grams is as follows:
1.80 x 10^-4 tons * 2,000 pounds/ton * 453.59237 grams/pound
Performing this calculation:
1.80 x 10^-4 tons * 2,000 * 453.59237 = 81.646826 grams (rounded to six decimal places).
Thus, 1.80 x 10^-4 tons is equivalent to 81.646826 grams.
Please help me. ? :)
Answers and explanation:
To answer these questions you use a periodic table.
A is In because it has 49 protons and In is element number 49.
B is 27 because Co is element number 27.
C is 73 because Ta is element number 73.
D is 49 because the number of electrons in an atoms is always equal to the number of protons.
E is 56 because the atomic number of Ba is 56.
F is 54 because 56 - 54 = 2. The charge is equal to the number of protons minus the number of electrons.
G is 66. The number of neutrons is equal to the atomic mass minus the number of protons. 115 - 49 = 66.
H is 108 because 181 - 73 = 108.
I is 32. The atomic mass of an element is equal to the amount of protons plus the amount of neutrons. So 16 + 16 = 32.
What is the density of a 19.3-gram object that displaces 12 cubed centimeters of water
Answer:
1.608 g/cm3
Explanation:
Formula:
D=m/v
d= density
m= mass
v= volume
Given data:
Mass= 19.3 g
Volume= 12 cm3
The volume of water displaces by object is 12 cm³ which means that object hold the volume of 12 cm³
Now we will put the values in formula:
D=19.3 g/ 12 cm3= 1.608 g/cm3
so the density of object is 1.608 g/cm3
Which set of coefficients would balance the following chemical equation?
H3PO4 + RbOH → H2O + Rb3PO4
Question 3 options:
2H3PO4 + RbOH → 3H2O + Rb3PO4
H3PO4 + RbOH → H2O + Rb3PO4
H3PO4 + RbOH → 2H2O + Rb3PO4
H3PO4 + 3RbOH → 3H2O + Rb3PO4
Answer:
H3PO4 + 3RbOH > 3H20 + Rb3PO4
Explanation:
The chemical equation H3PO4 + RbOH → H2O + Rb3PO4 is correctly balanced as H3PO4 + 3RbOH → 3H2O + Rb3PO4, based on the principle of conservation of atoms.
Explanation:The subject here is balancing chemical equations which is a core topic in high school chemistry. Balancing chemical equations involves adjusting the coefficients of the reactants and products to ensure that the number of atoms of each element is equal on both sides of the equation.
In the given equation H3PO4 + RbOH → H2O + Rb3PO4, the correct set of coefficients that balance the equation are H3PO4 + 3RbOH → 3H2O + Rb3PO4. So, for every one molecule of phosphoric acid (H3PO4), three molecules of Rubidium hydroxide (RbOH) react to form three molecules of water (H2O) and one molecule of Rubidium phosphate (Rb3PO4).
Learn more about Balancing Chemical Equations here:https://brainly.com/question/28294176
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Which phrase best discribes wave motion
Answer:
any sound really do you have a multiple choice answer
Explanation:
Answer:
we need some more answer so we can answer them
intrusive igneous rocks form?
Answer:
Intrusive, or plutonic, igneous rocks form when magma cools slowly below the Earth's surface. Most intrusive rocks have large, well-formed crystals. Examples include granite, gabbro, diorite and dunite.
Answer:
Intrusive, or plutonic, igneous rocks form when magma cools slowly below the Earth's surface. Most intrusive rocks have large, well-formed crystals. Examples include granite, gabbra, diorite and danite.
sorry if i spelled things wrong
Compare mechanical energy and thermal
energy.
Answer:
Explanation:
Mechanical and thermal energy are both different forms of energy. They can be converted from one to another. Some systems relies solely on this form of energy conversion between these types of interactions.
Mechanical energy is a form of energy that is due to the motion of a body.
Thermal energy is due to the temperature changes between bodies.
Both forms of energy are not related but they can be converted from one from to anther.
Nuclear energy could come from
Answer:
splitting of Barium atom
Explanation:
I just did the test :)
Which law states that the volume and absolute temperature of a fixed quantity of gas are directly proportional under constant pressure conditions?
Boyle’s law
Charles’s law
Dalton’s law
Gay-Lussac’s law
Answer:
Charles law
Explanation:
Relationship between volume and absolute temperature is given by Charles's law.
According to Charles's law, at constant pressure, volume of a gas of a fixed quantity is directly proportional to the absolute temperature.
Mathematically Charles's law is expressed as:
[tex]V \propto T[/tex]
Charles's law is applicable only for ideal gases.
Bolyles's law gives relationship between pressure and volume at fixed temperature.
Gay-Lussac’s law gives the relationship between pressure of a gas and its absolute temperature.
Dalton's law gives the relationship between pressure of the mixture of non reacting gases and partial pressure of individual gas.
Therefore, among, Charles's law is the correct opion.