Heat is released.
When a chemical change occurs, energy comes out of the atoms which causes heat.
Answer: Option (A) is the correct answer.
Explanation:
Chemical changes are defined as the change which tend to show difference in chemical composition of a substance.
For example, toxicity, reactivity, combustion etc are all chemical properties.
So, in the given situation formation of bubbles shows that a gas has been formed which is a chemical change.
A chemical change will always lead to the formation of a new compound and this change is irreversible in nature by any physical means.
On the other hand, a change which is unable to bring any difference in chemical composition of a substance is known as a physical change.
For example, change in shape, size, mass, volume etc are all physical properties.
Thus, we can conclude that a gas is formed is an indication that a chemical change has occurred.
The potential energy on a spring is proportional to the square of which of these quantities
Final answer:
The potential energy stored in a spring is proportional to the square of the displacement (x) from its undeformed position, as expressed by the formula PE_s = ½ kx².
Explanation:
The potential energy on a spring is proportional to the square of the displacement (x) from its undeformed position. When a spring is stretched or compressed by a distance x, the work done is stored as potential energy. This energy can be expressed by the formula PE_s = ½ kx², where k is the spring's force constant. At maximum compression or stretch, all the energy in the spring is potential, and when the spring passes through the equilibrium point, it possesses kinetic energy, which is also proportionate to the square of the amplitude of the motion.
4. the number that indicates the number of protons in the atoms
Answer:electrons indicates to the no of protons because they are same in number.
Explanation:
Taglines Definition: Example:
ILL GIVE BRAINLIEST
Answer:
Definition: a catchphrase or slogan, especially as used in advertising, or the punchline of a joke
EX: Walmart's tagline – Save money. Live better.
A tagline is a memorable phrase used in advertising or promotion that encapsulates the essence of what it's promoting. For instance, Nike's 'Just Do It' is an example of a tagline.
A tagline is a catchphrase or a slogan that is used to advertise or promote a product, service, or entity, such as a company, brand, movie, book, or campaign. These brief, memorable phrases aim to leave a lasting impression on the consumer, often encapsulating the essence of what they're promoting.
Example of a Tagline:
An example of a well-known tagline is 'Just Do It' by Nike. This simple yet powerful message encourages people to take action and emphasizes the brand's association with determination, resilience, and achievement in sports and life.
Density Word Problems
Use the following formula to answer the problems. You must SHOW your work!
density = volume
density =
mass
or, in short form:
1. What is the density of carbon dioxide gas if 0.196 g occupies a volume of 100 mL?
Answer:
3CMx 3 cm x 3cm=27CM
2. A block of wood 3.0 cm on each side and has a mass of 27 g. What is the density of
this block?
Answer:
Answer:
3. An irregularly shaped stone was lowered into a graduated cylinder holding a volume
of water equal to 2.0 mL. The height of the water rose to 7.0 mL. If the mass of the
stone was 25 g, what was its density?
Using the formula for density (mass/volume), it's determined that the density of carbon dioxide gas is 0.00196 g/mL, the block of wood is 1 g/mL, and the irregular stone is 5 g/mL.
Explanation:To answer these density problems, we use the formula: density = mass/volume.
1. For carbon dioxide gas, the mass is 0.196 g and the volume is 100 mL. Therefore, the density equals 0.196/100 = 0.00196 g/mL.
2. For the block of wood, the volume is the cube of the side length (3 cm x 3 cm x 3 cm = 27 cm^3 = 27 mL, as 1 cm^3 = 1 mL). The mass is 27 g, so the density equals 27/27 = 1 g/mL.
3. The irregular stone displaces water volume from 2.0 mL to 7.0 mL, which gives a total volume of 5.0 mL. Mass is 25 g, so the density equals 25/5 = 5 g/mL.
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Science is a unique field of thought because it relies on _______ to describe the world. A Teachers and students B Observations and experimentation C Books and writings D Scientists and statements
Answer:
B) Observations and experimentation
Explanation:
this is the most suitable words to describe how is Science used in describing the world. we collect the knowledge in organized way and provide it with explanations and start to predict about the future world
ِAny Inventions are based on Science and no Inventions without Observations and experimentation
No one of us have went to a chemistry or a physics labs without using Observations and experimentation
What is the mass in grams of 16.3 mol of the element
nickel, Ni?
Answer:
The mass of 16.3 moles of nickel is 956. 647 g.
Explanation:
Given data:
moles of nickel = 16.3 mol
molar mass of nickel = 58.69 g/mol
mass in gram = ?
solution:
Formula:
number of moles = mass / molar mass
mass = number of moles × molar mass
mass = 16.3 mol × 58.69 g/mol
mass= 956. 647 g
To find the mass of 16.3 mol of nickel, multiply the number of moles by the molar mass of nickel, 58.693 g/mol, resulting in a mass of 956.9 grams.
Explanation:To find the mass in grams of 16.3 mol of the element nickel (Ni), you need to use the element's molar mass. As identified in the information provided, the molar mass of nickel is 58.693 g/mol. Applying this molar mass to the given number of moles (16.3 mol), you can calculate the mass as follows:
Mass = number of moles × molar mass
Mass = 16.3 mol × 58.693 g/mol
Mass = 956.8969 g
Therefore, the mass of 16.3 mol of nickel is 956.9 grams (rounded to one decimal place).
Which two particles are found in the nucleus of an atom?
O neutrons and electrons
O protons and electrons
O protons and neutrons
O neutrons and atoms
c. protons and neutrons are the two particles found in the nucleus of an atom
What is a proton?A proton is a subatomic particle found in the nucleus of every atom
What are protons and neutrons?
Protons and neutrons are in the center of the atom, making up the nucleus. Electrons surround the nucleus. Protons have a positive charge. Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite.
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Answer:
C
Explanation:
just took quiz
13. How many valence electrons does an atom
with 5 electrons, 5 neutrons, and 5 protons
have in its ground state?
A. 5
B.
4.
C.
D.
3
2
Answer:
The answer to your question is: 3
Explanation:
If an atom has 5 electrons, 5 neutrons and 5 protons, it means that the element is Boron. Boron is situated in the third group A, that means that is has 3 elements in its outermost shell.
Also, if we do the electronic configuration:
1s² 2s²2p¹
If we count the number of electron in the second level of energy, the result will be: 2 in s and 1 in p = 3. Those are the valence electrons.
What is the frequency of light with an energy of 124 kJ/mol?
Answer: = 3.11 x 10^14 s^-1
Explanation:
Use the formula E = hv
This formula uses the assumption that the unit for energy is in Joules/photon.
124 kJ = 124000J
To get 124000J/mol into a unit of J/photons, we need to divide by the number of photons in a mole, which is 6.022 x 10^23.
And thus, we need
124000/6.022 x 10^23 = 2.06 x 10^-19J/photon
We can plug it in to E = hv by
2.06 x 10^-19J = (6.63 x 10^-34 J s)(v) Isolate v by
v = (2.06 x 10^-19J)/(6.63 x 10^-34 J s)
= 3.11 x 10^14 s^-1
How many moles of Al(CN)3 are in 251 g of the compound?
Answer:
251 g of compound contain 2.39 moles.
Explanation:
Given data:
mass of compound Al(CN)3 = 251 g
moles = ?
Solution:
First of all we will calculate the molar mass of given compound.
molar mass of Al(CN)3 = 26.98 + (26 × 3)
molar mass of Al(CN)3 = 105 g/mol
Formula:
number of moles = mass/ molar mass
number of moles = 251 g / 105 g/mol
number of moles = 2.39 mole
Select all the correct answers.
Researchers are studying possible ways to use the process of nuclear fusion to generate electricity. In what ways would fusion be better than fission for use in power plants?
1._The fuel used for fusion is abundant in nature and easy to obtain.
2._Fusion occurs at ordinary temperatures and pressures.
3._The fusion process doesn’t require an energy input.
4._Fusion has fewer safety risks than fission.
5._Fusion doesn’t produce radioactive waste products.
Answer:
it is The fuel used for fusion is abundant in nature and easy to obtain and The fusion process doesn’t require an energy input ans Fusion has fewer safety risks than fission. and Fusion doesn’t produce radioactive waste products.
Explanation:
Answer:
The correct answer is option 5.
Explanation:
The process of nuclear fission takes place due to the dissociation of heavy atoms into lighter atoms, generating high energy particles in the procedure like alpha, neutrons, and beta particles. On the other hand, the process of nuclear fusion takes place by combining lighter atoms into heavier atoms generating very less radioactive constituents.
In the process of nuclear fusion, there are also lesser chances of a meltdown of a fusion reaction in comparison to a fission reaction, thus, minimizing the occurrences of an accident. The process of nuclear fusion is better in comparison to nuclear fission in generating electricity in power plants as fusion processes do not generate radioactive waste components.
In the process of nuclear fission, one projectile is required to hit the heavy element nucleus, and the reaction cannot be stopped and always generate radioactive elements as the side component. While in nuclear fusion an enormous amount of heat is required. The reaction can be stopped readily and the eventual component produced is not radioactive in nature, that is, environment-friendly.
Which has the greater EN:
Cl or Al?
Answer:
CL
because cleetus will rule the world
the pressure of a gas constant temperature is increased by a factor od 4 by what factor does the volume change
1/4
1/2
1
4
Answer:
[tex]\frac{1}{4}[/tex]
Explanation:
From the given problem, we are to find the factor number by which the volume of the compressed gas has changed through.
We apply Boyle's law to this problem because the condition of the reaction stipulates a constant temperature.
Boyle's law states "the volume of a given mass of gas is inversely proportional to its pressure provided that temperature remains constant". Mathematically, it is expressed as:
P₁V₁ = P₂V₂
P₁ is initial pressure on the gas
V₁ is the initial volume of the gas
P₂ is the final pressure of the gas
V₂ is the final volume of the gas
From the problem, we are to find the factor through which the volume changed:
P₁V₁ = P₂V₂
V₂ = [tex]\frac{P_{1} }{P_{2} } V_{1}[/tex]
Now:
P₁ = P₁
P₂ = 4P₁
V₂ = [tex]\frac{P_{1} }{4P_{1} } V_{1}[/tex]
Therefore, the factor of the volume change is [tex]\frac{1}{4}[/tex]
The study of chemicals and bonds is called chemistry.
The correct answer is option A which is 1/4.
What is ideal gas law?The ideal gas law, also called the general gas equation, is the equation of the state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitationsFrom the given problem, we are to find the factor number by which the volume of the compressed gas has changed. We apply Boyle's law to this problem because the condition of the reaction stipulates a constant temperature.
Boyle's law states "the volume of a given mass of gas is inversely proportional to its pressure provided that temperature remains constant". Mathematically, it is expressed as:
P₁V₁ = P₂V₂
Where
P₁ is initial pressure on the gasV₁ is the initial volume of the gasP₂ is the final pressure of the gasV₂ is the final volume of the gasFrom the problem, we are to find the factor through which the volume changed:
P₁V₁ = P₂V₂
V₂ = [tex]\frac{P_1}{P_2}*V_1[/tex]
Now:
P₁ = P₁
P₂ = 4P₁
Hence
V₂ = [tex]\frac{P_1}{4P_2}*V_1[/tex]
Therefore, the factor of the volume change is 1/4.
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What two properties of a gas depend on its container?
One property is it's volume. I am not sure if the second
Answer:
Volume and pressure.
Explanation:
The gases represent the physical state of matter whose values of volume, density or shape are not defined. They have a high degree of disorder caused by the free displacement of the particles that make them up (atoms, molecules or ions - usually molecules) and are objects of study because they have great applicability in everyday life, and because they are the material layer in which we keep most contact, after all, normally our whole body is in contact with gases (atmospheric air).
The properties of the gases are variable, that is, because there are certain and specific spaces between their constituents (which can increase or decrease) the volume, density, pressure, viscosity can be changed. The smaller the container in which the gas is containing, the smaller its volume and the higher its pressure, for example.
PLEASE HELP ASAP !!! How to balance equations with brackets? Like Pb(NO3)2? How many of each element is there?
Answer:
When you have those kind of compounds you have to multiply each element inside the bracket by the subscript outside the bracket. Here you have 1 Pb, 2 N and 6 O.
Explanation:
Answer:
Replace the formulas inside the parentheses with single letters
Explanation:
Here's an equation with lots of parentheses.
(NH₄)₃PO₄ + Pb(NO₃)₂ ⟶ NH₄NO₃ + Pb₃(PO₄)₂
It looks impossible to balance, doesn't it?
One way to balance the equation is to recognize that the polyatomic ions (the formulas inside the parentheses) stay together.
Then we can make some substitutions.
Let A = NH₄, X = PO₄, and Y = NO₃
Then the equation becomes
A₃X + PbY₂ ⟶ AY + Pb₃X₂
Here's how to balance it.
1. Start with the most complicated formula, Pb₃X₂, and put a 1 in front of it.
A₃X + PbY₂ ⟶ AY + 1Pb₃X₂
2. Balance Pb
We have fixed three atoms of Pb on the right, so we need three atoms of Pb on the left. Put a 3 in front of PbY₂.
A₃X + 3PbY₂ ⟶ AY + 1Pb₃X₂
3. Balance X
We have fixed two atoms of X on the right, so we need two atoms of X on the left. Put a 2 in front of A₃X.
2A₃X + 3PbY₂ ⟶ AY + 1Pb₃X₂
4. Balance A
We have fixed 6 atoms of A on the left, so we need 6 atoms of A on the right. Put a 6 in front of AY.
2A₃X + 3PbY₂ ⟶ 6AY + 1Pb₃X₂
Every formula has a coefficient, and the equation is now balanced.
Next, we replace the original formulas in the equation.
The balanced equation is
2(NH₄)₃PO₄ + 3Pb(NO₃)₂ ⟶ 6NH₄NO₃ + 1Pb₃(PO₄)₂
How is weight affected by the location?
This word means that one event happens at the same time as another event
Answer:
Meanwhile
Explanation:
Think of a comic book, or a superhero show, you usually see the protagonist, or the hero, doing something like saving an innocent pedestrian, or helping a little old lady across a street, then the screen will flash and say 'meanwhile' which means while this was happening, this was also happening.
An example could be in The Wizard of Oz, when Dorothy is walking with her friends through The Haunted Forest, you see the Wicked Witch of the East, peering through her crystal ball, unto Dorothy. To summarize what was happening you could say,
'Meanwhile, as Dorothy and her friends walked through The Haunted Forest, The Wicked Witch watched their stroll.'
Really hopes this helps!
A nugget of gold with a mass of 521 g is added to 50.0mL of water.The water level rises to a volume of 77.0mL. What is the density of the gold?
Answer:
The question to your answer is:
Explanation:
Data
mass = 521 g
Water volume = 50.0 ml
Increase of water = 77 ml
Formula
density = mass / volume
First substract the final volume to the initial volume
Volume of gold = 77 - 50 = 27 ml
Now, use the formula
density = 521 / 27 ml = 19.3 g/ml
The density of the gold nugget is 19.3 g/mL.
To find the density of the gold, we need to calculate the volume of the gold nugget from the water displacement and then divide the mass of the gold by this volume. The volume of the gold nugget can be determined by calculating the difference in the water level before and after the gold was added. This value is 77.0 mL - 50.0 mL = 27.0 mL. Since the density (d) can be calculated using the formula d = mass/volume, we can substitute the given mass of 521 g and the calculated volume of 27.0 mL to find the density.
Using these values gives us: density = 521 g / 27.0 mL = 19.3 g/mL.
Therefore, the density of the gold is 19.3 g/mL, which is consistent with the known density of gold.
Which statements about Earth’s crust are true? Check all that apply. The crust includes soil, rock, and water. There are three different kinds of crust. The crust is thickest under the ocean. The ocean crust is made of young rocks. The ocean crust is denser than continental crust.
Answer:
Options (1), (4) and(5)
Explanation:
The earth's lithosphere is divided into two types of crust, that are commonly known as-
Continental crust- It has a thickness of about 35-40 km and is comprised of minerals such as silicates, alkali feldspar that is less dense in nature. Oceanic crust- It has a thickness of about 7-10 km and is comprised of denser minerals such as olivine, pyroxene, and potash feldspar.Both the type of crust are comprised of water, rock as well as soil. The rocks of oceanic crust are much younger than the continental crust because the oceanic crust is formed from the seafloor spreading where the new materials are added to the crust along the mid-oceanic ridge. The rocks at this boundary are the youngest. On the other hand, the continental crust is the oldest and is present from the time of the formation of the earth. The denser oceanic crust subducts below the lighter continental crust in a convergent plate boundary.
Thus, the correct answers are options (1), (4) and(5).
Answer:the answers are 1,4 and 5
Explanation:hope this helps
Consider the following precipitation reaction: 2Na3PO4(aq)+3CuCl2(aq)→ Cu3(PO4)2(s)+6NaCl(aq)
What volume of 0.184 M Na3PO4 solution is necessary to completely react with 94.6 mL of 0.108 M CuCl2?
Answer:
V= 37.0 mL
Explanation:
First find the moles of the known substance (CuCl2)
n= cv
where
n is moles
c is concentration
v is volume ( in litres)
n= 0.108 × 0.0946
n=0.0102168
Using the mole ratio in the balanced reaction, we can find the moles of Na3PO4
n (Na3PO4)= n (CuCl2) × 2/3
=0.0102168 × 2/3
=0.0068112
Now we have all the necessary values to calculate the volume
v=n/c
v= 0.0068112/0.184
v= 0.0370173913 L
v= 37.0 mL
37 ml volume of 0.184 M Na₃PO₄ solution is necessary to completely react with 94.6 mL of 0.108 M CuCl₂ solution.
What is molarity?The molarity is the way to express the concentration of the solution. The molarity of any solution can be calculated by dividing the number of mos of solute by the volume of the solution in liters. The unit of the molarity of the solution is mol/L or represented by M.
Given the chemical equation of precipitation reaction:
2Na₃PO₄ (aq) + 3CuCl₂ (aq) → Cu₃(PO₄)₂ (s) + 6NaCl (aq)
Given the volume of 0.108 M CuCl₂ solution = 94.6 ml = 0.946 L
The number of moles of CuCl₂ = M ×V = 0.108 × 0.846 = 0.01022 mol
If 3 moles of CuCl₂ completely react with Na₃PO₄ = 2
Then 0.01022 moles of CuCl₂ will react with Na₃PO₄ :
= (2/3) × 0.01022
= 0.00681 mol
The volume of 0.184 M of Na₃PO₄ required = 0.00681 /0.184 = 37 ml
Therefore, 37 ml of Na₃PO₄ solution is required to completely react with 94.6mL of 0.108 M CuCl₂.
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Boyle's Law represents the relationship of volume as pressure changes. The constants of Boyle's Law are:
pressure and number of molecules of gas
volume and temperature
pressure and temperature
temperature and number of molecules of gas
pressure and volume
Answer:
pressure and volume
Explanation:
Boyle's law states that the volume of a fixed mass of gas is inversely proportional to it's pressure at constant temperature.
Answer:
D. pressure and volume
Explanation:
Boyle’s law states that,
For a given amount of a gas, Pressure is inversely proportional to its volume at constant temperature
Thus the expression is
PV = constant (T and n are constant)
When there is a change in pressure and volume we make use of the expression
[tex]P_1 V_1=P_2 V_2[/tex] (T and n are constants)
Where [tex]P_1[/tex] and [tex]V_1[/tex] are the Initial pressure and volume and
[tex]P_2[/tex] and [tex]V_2[/tex] are the final pressure and volume
Inversely proportional means when one increases the other one decreases. That is as per Boyle’s law when Pressure increases the volume will decrease and vice versa.
Magnesium bromide is a binary ionic compound. From its formula, MgBr2, how do you know that
Mg is the metal?
Answer: Magnesium loses electrons to form [tex]Mg^{2+}[/tex]
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. Metals donate the electron and forms a positively charged ion called as cation. Non metals accept the electrons and forms a negatively charged ion called as anion.
Electronic configuration of magnesium:
[tex][Mg]:12: 1s^22s^22p^63s^2[/tex]
Magnesium atom will loose one electron to gain noble gas configuration and form magnesium cation with +2 charge.
[tex][Mg^{2+}]:10:1s^22s^22p^63s^0[/tex]
Electronic configuration of bromine
[tex][Br]:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5[/tex]
Bromine atom will gain one electron to gain noble gas configuration and form bromide ion with -1 charge.
[tex][Br^-]=1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]
Thus as magnesium forms a cation , it is the metal.
The element _____ is not one of the four most common in your body. hydrogen nitrogen oxygen sodium
Answer:
Nitrogen
Explanation:
Answer:
Explanation:
#9 Sodium (Na) - 0.15% - Sodium is an important electrolyte. Like potassium, it is used for nerve signaling. Sodium is one of the electrolytes that helps regulate the amount of water in the body.
During Trial 2, what allowed you to determine that aluminum was the limiting reactant? Check all that
apply.
All of the copper dissolved.
All of the aluminum dissolved.
The solution turned clear.
The number of grams of copper(II) chloride used in the reaction was greater than the number of
grams of aluminum.
The molar ratio of copper(II) chloride to aluminum was greater than 3:2, the equation's molar ratio.
Answer:
b & e
Explanation:
Answer:
B and E
Explanation:
On Edge 2021
In a value, any non-zero digit is considered a significant digit. (Zeroes may or may not be significant.) What is the minimum number of significant digits in 828,000,000
Answer:
The minimum number of significant digits in 828,000,000 is 3.
Explanation:
This is because there are 3 non-zero digits that are considered significant.
The minimum number of significant digits in 828,000,000 is three.
Significant digitsIn the given number, all non-zero digits (8, 2, and 8) are considered significant digits. The zeroes in this case are placeholders and do not contribute to the number's significant digits.
Therefore, the minimum number of significant digits in 828,000,000 is three, as it is determined by the count of non-zero digits in the number.
This explanation emphasizes the rules for identifying significant digits in a value, focusing on the actual non-zero digits that convey meaningful information.
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Which orbitals form a pi bond?
Final answer:
A pi bond is formed by the side-by-side overlap of unhybridized 2pz orbitals on the carbon and the oxygen.
Explanation:
The pi bond is formed by the side-by-side overlap of unhybridized 2pz orbitals on the carbon and the oxygen. Just like in alkenes, the 2pz orbitals that form the pi bond are perpendicular to the plane formed by the sigma bonds.
For the following aqueous reaction, complete and balance the molecular equation and write a net iconic equatio, making sure to include the physical states of the compounds:
Potassium carbonate + Strontium nitrate
Answer:
Balance molecular equation:
K2CO3(aq) + Sr(NO3)2(aq) → SrCO3(s) + 2KNO3(aq)
Net ionic equation:
CO3∧-2(aq) + Sr∧+2(aq) → SrCO3(s)
Explanation:
Potassium carbonate = K2CO3
Strontium nitrate = Sr(NO3)2
Chemical equation:
K2CO3 + Sr(NO3)2 → SrCO3 + KNO3
Balance chemical equation with physical states:
K2CO3(aq) + Sr(NO3)2(aq) → SrCO3(s) + 2KNO3(aq)
Ionic equation:
2K+(aq) + CO3∧-2(aq) + Sr∧+2(aq) + 2NO∧-3(aq) → SrCO3(s) + 2K+(aq) + 2NO∧-3(aq)
Net ionic equation:
CO3∧-2(aq) + Sr∧+2(aq) → SrCO3(s)
2K+ and 2NO∧-3 ions are spectator ions that's way these are not written in net ionic equation.
Spectator ions:
These are the ions that are present same on both side of chemical reaction and does not effect the equilibrium.
The molecular equation for the reaction between potassium carbonate and strontium nitrate is K2CO3 (aq) + Sr(NO3)2 (aq) → 2KNO3 (aq) + SrCO3 (s). The complete ionic equation is 2K+ (aq) + CO3^2- (aq) + Sr^2+ (aq) + 2NO3^- (aq) → 2K+ (aq) + 2NO3^- (aq) + SrCO3 (s). The net ionic equation is CO3^2- (aq) + Sr^2+ (aq) → SrCO3 (s).
Explanation:The molecular equation for the reaction between potassium carbonate and strontium nitrate is:
K2CO3 (aq) + Sr(NO3)2 (aq) → 2KNO3 (aq) + SrCO3 (s)
The complete ionic equation for the reaction is:
2K+ (aq) + CO32- (aq) + Sr2+ (aq) + 2NO3- (aq) → 2K+ (aq) + 2NO3- (aq) + SrCO3 (s)
The net ionic equation for the reaction is:
CO32- (aq) + Sr2+ (aq) → SrCO3 (s)
How many hydrogen Adams are there in 3.14 moles of H2O
Answer:
3.783×10²⁴
Explanation:
We know that one mole of water contain two moles of hydrogen atom and one mole of oxygen atom. shown in following equation:
2H₂ + O₂ → 2H₂O
And
1 mole of hydrogen = 6.022×10²³ atoms of hydrogen
The number 6.022×10²³ is called Avogadro number and it is the number of atoms in one mole of substance. While we have to find the hydrogen atoms in 3.14 moles of water
So the factor 3.14 given in the question contain
3.14×2×6.022×10²³ number of hydrogen atoms which is equal to the 3.783×10²⁴.
Answer:
1.89×10^24 atoms
Explanation:
I mole of hydrogen molecule contains 6.02×10^23 atoms. This is known as the Avogadro's number. The Avogadro's number gives the number of elementary entities contained in one mole of a substance.
One mole of a substance is the amount of that substance that contains the same number of elementary entities as 12g of C-12
Hence 3.14 moles of hydrogen will contain 3.14 ×6.02×10^23= 1.89×10^24 atoms
If the reaction produced 15.5 g CO2, how many grams of heptane were burned?
Answer:
5 g of heptane were burned.
Explanation:
Given data:
Mass of CO₂ produced = 15.5 g
Mass of heptane burned = ?
Solution:
Balance chemical equation:
C₇H₁₆ + 11O₂ →7CO₂ + 8H₂O
First of all we will calculate the moles of CO₂ produced.
Number of moles = mass / molar mass
Molar of CO₂ = 44 g/mol
Number of moles = 15.5 g / 44 g/mol
Number of moles = 0.3523 mol
Now we will compare the moles of CO₂ and C₇H₁₆ from balance chemical equation
CO₂ : C₇H₁₆
7 : 1
0.3523 : 1/7 × 0.3523 = 0.05 mol
Mass of C₇H₁₆:
Number of moles = mass / molar mass
Mass = number of moles × molar mass
Mass = 0.05 mol / 100 g/mol
Mass = 5 g
What evidence is there that electrons move around in definite pathways around the
nucleus?
What evidence is there that electrons m
Answer:
Absorption and emission spectra
Explanation:
This is occurs when an atom either absorbs or emits energy when bombarded by a source.
Neils Bohr predicted that electrons moves round in the atom in distinct orbitals according to their energy. An electron in its ground state can become excited if it gains sufficient energy which surpasses that of its ground state configuration. An atom can also move from higher energy levels to lower ones. During the descent, energy is given off in form of emission spectra.
Absorption occurs when electrons in an atom absorbs energy from incoming radiation and they re-radiate it in all directions. This is given off as a spectra and can be observed for such electron.
Final answer:
Quantum mechanics replaced the idea of electrons moving in fixed orbits with the concept of orbitals, where electrons have a high probability of being found. Evidence for this includes distinct atomic spectra and quantum numbers that match experimental data.
Explanation:
The question about the behavior of electrons around the nucleus is a fundamental concept in chemistry and physics. The early model by Niels Bohr suggested that electrons move in definite circular paths or orbits around the nucleus, akin to planets orbiting the sun. However, this model was succeeded by quantum mechanics, which describes electron behavior as a set of probabilities rather than definite paths.
Quantum mechanics introduced the concept of electron orbitals, which describe regions of space around the nucleus where there is a high probability of finding an electron. One piece of experimental evidence is the atomic spectra, which show distinct lines corresponding to electrons moving between energy levels in an atom. This indicates that electrons occupy specific energy states rather than moving randomly.
Another supporting evidence comes from quantum numbers, which describe the properties of electron orbitals and help explain the arrangement of electrons in atoms. These quantum numbers arise naturally from the equations of quantum mechanics and match a vast array of experimental data.