Atomic Structure and Properties - AP Chemistry
Card 1 of 1924
How many moles are in 610 atoms of silver?
How many moles are in 610 atoms of silver?
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The reason the answer has 2 significant figures, is because the given measurement has 2 significant figures. Remember: in non-decimal numbers, zeros only count if in between non-zero numbers.
The reason the answer has 2 significant figures, is because the given measurement has 2 significant figures. Remember: in non-decimal numbers, zeros only count if in between non-zero numbers.
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A pure sample of
is found to contain 71g of chlorine atoms. What is the mass of the sample?
A pure sample of is found to contain 71g of chlorine atoms. What is the mass of the sample?
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First, find how many moles of chlorine are present in the sample:

Because the ratio of moles of
to moles of
is 1:1, there are also 2 moles of
. The next step is to find the mass of 2 moles of
.

First, find how many moles of chlorine are present in the sample:
Because the ratio of moles of to moles of
is 1:1, there are also 2 moles of
. The next step is to find the mass of 2 moles of
.
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A chemist has found that 2.0 moles of a mysterious compound contained 48g of carbon, 8g of hydrogen, and 64g of oxygen. What is the molecular formula of the compound?
A chemist has found that 2.0 moles of a mysterious compound contained 48g of carbon, 8g of hydrogen, and 64g of oxygen. What is the molecular formula of the compound?
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Find the number of moles of each element.




If the chemist has 2.0 moles of the compound, 1 mole would contain half as much. So 1mol of carbon, 4mol of hydrogen, and 2mol of oxygen, which forms acetic acid

Find the number of moles of each element.
If the chemist has 2.0 moles of the compound, 1 mole would contain half as much. So 1mol of carbon, 4mol of hydrogen, and 2mol of oxygen, which forms acetic acid
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How many atoms are there in
moles of
?
How many atoms are there in moles of
?
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This question is asking us to determine how many atoms there are in
moles of
. Rather than asking for the number of molecules, our final answer will need to tell us the number of atoms. Since there are
atoms for every molecule of
, we'll first need to find out how many molecules there are.

This question is asking us to determine how many atoms there are in moles of
. Rather than asking for the number of molecules, our final answer will need to tell us the number of atoms. Since there are
atoms for every molecule of
, we'll first need to find out how many molecules there are.
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Using the PES spectra above, what element is illustrated?

Using the PES spectra above, what element is illustrated?
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The peak at ~ 40 MJ binding energy corresponds to the 1s orbital. Since there are peaks at lower binding energy, it is implied that this orbital is filled (by 2 electrons). There are two peaks at lower binding energy corresponding to the 2s and 2p orbitals, respectively. The 2s peak has the same intensity as the 1s peak indicating it has the same number of electrons (2). The 2p peak is 3/2 as tall as the 2s peak and indicates that indicates it has 3 electrons in the orbital. The electron configuration of 1s22s22p3 makes the element N.
The peak at ~ 40 MJ binding energy corresponds to the 1s orbital. Since there are peaks at lower binding energy, it is implied that this orbital is filled (by 2 electrons). There are two peaks at lower binding energy corresponding to the 2s and 2p orbitals, respectively. The 2s peak has the same intensity as the 1s peak indicating it has the same number of electrons (2). The 2p peak is 3/2 as tall as the 2s peak and indicates that indicates it has 3 electrons in the orbital. The electron configuration of 1s22s22p3 makes the element N.
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Using the PES spectra above, what answer explains the differences in the position and intensity of the 3s peaks between Na and Mg?

Using the PES spectra above, what answer explains the differences in the position and intensity of the 3s peaks between Na and Mg?
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Mg has a Z=12 while Na is Z=11. The increased number of protons in Mg gives rise to a greater effective nuclear charge. This greater effective nuclear charge binds the electrons in their respective orbitals more tightly than an element with a lower effective nuclear charge. The peak height of Mg is 2x that of Na for the 3s orbital because it has twice the electrons present.
Mg has a Z=12 while Na is Z=11. The increased number of protons in Mg gives rise to a greater effective nuclear charge. This greater effective nuclear charge binds the electrons in their respective orbitals more tightly than an element with a lower effective nuclear charge. The peak height of Mg is 2x that of Na for the 3s orbital because it has twice the electrons present.
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Using the spectra above, answer the following: Why is the oxygen 1s electrons further to the right than the nitrogen 1s orbital?

Using the spectra above, answer the following: Why is the oxygen 1s electrons further to the right than the nitrogen 1s orbital?
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Oxygen has a Z=8 vs nitrogen’s Z=7. This greater effective nuclear charge binds the electrons in their respective orbitals more tightly than an element with a lower effective nuclear charge.
Oxygen has a Z=8 vs nitrogen’s Z=7. This greater effective nuclear charge binds the electrons in their respective orbitals more tightly than an element with a lower effective nuclear charge.
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Using the spectra above, answer the following: What is the electron configuration of the element shown above?
Using the spectra above, answer the following: What is the electron configuration of the element shown above?
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The binding energy at ~ 53 Mj represents the 1s orbital. With other peaks present, this 1s orbital is fully occupied by 2 electrons. The peaks at lower energy would correspond to the 2s and 2p, respectively. Since the 2p peak is twice the intensity of the 2s or 1_s_ peak, it has twice the electrons (4). This gives the electron configuration 1s22s22p4.
The binding energy at ~ 53 Mj represents the 1s orbital. With other peaks present, this 1s orbital is fully occupied by 2 electrons. The peaks at lower energy would correspond to the 2s and 2p, respectively. Since the 2p peak is twice the intensity of the 2s or 1_s_ peak, it has twice the electrons (4). This gives the electron configuration 1s22s22p4.
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Using the spectra above, answer the following: What is the wavelength required, in m, to remove a valence electron from the element shown above?

Using the spectra above, answer the following: What is the wavelength required, in m, to remove a valence electron from the element shown above?
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Step 1. Convert the Binding Energy from MJ/mol to J
x
x 
Step 2:


Step 1. Convert the Binding Energy from MJ/mol to J
x
x
Step 2:
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Which of the following set of quantum numbers are not allowed: (a) n = 3, l = 2, ml = 0
(b) n = 2, l = 4, ml = –1 (c) n = 2.5, l = 1, ml = –1?
Which of the following set of quantum numbers are not allowed: (a) n = 3, l = 2, ml = 0
(b) n = 2, l = 4, ml = –1 (c) n = 2.5, l = 1, ml = –1?
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The sets of quantum numbers needs to follow the following rules: n (principal quantum
number) needs to be a positive integer, l can have any integral value from 0 to n – 1, and ml can range from –l to l. The only quantum numbers that follows these rules are (a).
The sets of quantum numbers needs to follow the following rules: n (principal quantum
number) needs to be a positive integer, l can have any integral value from 0 to n – 1, and ml can range from –l to l. The only quantum numbers that follows these rules are (a).
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What does the azimuthal quantum number reveal about the quantum mechanical model of an atom?
What does the azimuthal quantum number reveal about the quantum mechanical model of an atom?
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The azimuthal quantum number is the second quantum number, designated by the letter l. It gives the shape and number of subshells in a principal energy level (shell).
The azimuthal quantum number is the second quantum number, designated by the letter l. It gives the shape and number of subshells in a principal energy level (shell).
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If an electron falls from the energy level of n = 5 to the ground state of n = 1, what is most likely to occur?
If an electron falls from the energy level of n = 5 to the ground state of n = 1, what is most likely to occur?
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There is not enough information given in the question stem to determine if the velocity of the electron is changed. We can definitively determine, however, the electron will lose energy and a photon will be emitted.
There is not enough information given in the question stem to determine if the velocity of the electron is changed. We can definitively determine, however, the electron will lose energy and a photon will be emitted.
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In terms of the principal quantum number,
, how many electrons can be accommodated in a given energy level?
In terms of the principal quantum number, , how many electrons can be accommodated in a given energy level?
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For any n, the energy level can hold 2n2 electrons, since there are two electrons for each orbital.
For any n, the energy level can hold 2n2 electrons, since there are two electrons for each orbital.
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Which is the most stable electron configuration of Fe (II) ion?
Which is the most stable electron configuration of Fe (II) ion?
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A fully filled orbital is generally more stable than a half-filled orbital. The splitting of the energy levels is also dependent on the geometry of the compound that one is analyzing. The 4s electrons are of higher energy than the 3d electrons, thus are lost first, leaving half filled d orbitals, which is the most stable configuration.
A fully filled orbital is generally more stable than a half-filled orbital. The splitting of the energy levels is also dependent on the geometry of the compound that one is analyzing. The 4s electrons are of higher energy than the 3d electrons, thus are lost first, leaving half filled d orbitals, which is the most stable configuration.
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How does energy vary as the quantum number (n) of an orbital changes?
How does energy vary as the quantum number (n) of an orbital changes?
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The energy of an electron is related to the quantum number by the equation E = -R/n2, where R is constant. The negative charge make it so that as n increases, the numerical value of the energy becomes less negative, approaching zero. Thus the energy increases as n increases.
The energy of an electron is related to the quantum number by the equation E = -R/n2, where R is constant. The negative charge make it so that as n increases, the numerical value of the energy becomes less negative, approaching zero. Thus the energy increases as n increases.
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Which atomic subshell fills with electrons first: 3d or 4s?
Which atomic subshell fills with electrons first: 3d or 4s?
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For the 3d subshell, n (principal quantum number) = 3 and l (azimuthal quantum number) = 2, so n + l = 5. For the 4s subshell, n = 4 and l = 0, so n+l = 4. From this information, we can see that the 4s subshell has lower energy and will fill with electrons first.
For the 3d subshell, n (principal quantum number) = 3 and l (azimuthal quantum number) = 2, so n + l = 5. For the 4s subshell, n = 4 and l = 0, so n+l = 4. From this information, we can see that the 4s subshell has lower energy and will fill with electrons first.
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Which is the correct orbital notation for Copper?
Which is the correct orbital notation for Copper?
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The elements in copper's group will fill the d orbital at the expense of having a half filled s orbital. This is because this configuration is more stable than a full s orbital and d orbital with 9/10 spots filled.
The elements in copper's group will fill the d orbital at the expense of having a half filled s orbital. This is because this configuration is more stable than a full s orbital and d orbital with 9/10 spots filled.
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What is the electron configuration for Chromium?
What is the electron configuration for Chromium?
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6 more electrons are present in chromium than argon. It's more stable for d orbitals to be half-filled. Thus, one electron will fill each of the 5 d orbitals.
6 more electrons are present in chromium than argon. It's more stable for d orbitals to be half-filled. Thus, one electron will fill each of the 5 d orbitals.
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What is the angular momentum quantum number for the highest energy orbital in the ground state Manganese atom?
What is the angular momentum quantum number for the highest energy orbital in the ground state Manganese atom?
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First, we will write out the electron configuration for the ground state Manganese atom, considering only the valence electrons:
![[Ar]4s^23d^5](https://vt-vtwa-assets.varsitytutors.com/vt-vtwa/uploads/formula_image/image/20029/gif.latex)
The orbitals highest in energy will be filled last, so our highest energy orbitals are
orbitals.
The angular momentum quantum number describes the shape of the orbital, with
orbitals corresponding to
,
orbitals corresponding with
, and
orbitals corresponding to
, and so on.
We are considering a
orbital, so
.
First, we will write out the electron configuration for the ground state Manganese atom, considering only the valence electrons:
The orbitals highest in energy will be filled last, so our highest energy orbitals are orbitals.
The angular momentum quantum number describes the shape of the orbital, with orbitals corresponding to
,
orbitals corresponding with
, and
orbitals corresponding to
, and so on.
We are considering a orbital, so
.
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What is the electron configuration for
?
What is the electron configuration for ?
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First, we will write down the electronic configuration for the ground state of Cobalt:
![[Ar]4s^23d^7](https://vt-vtwa-assets.varsitytutors.com/vt-vtwa/uploads/formula_image/image/20077/gif.latex)
Remember that a half-filled
orbital is very stable, and when it is possible for an ion to have a
electron configuration it will. In order to attain this, two electrons will be removed from the
orbitals and one will be removed from the
orbital, yielding:
![[Ar]4s^13d^5](https://vt-vtwa-assets.varsitytutors.com/vt-vtwa/uploads/formula_image/image/20082/gif.latex)
First, we will write down the electronic configuration for the ground state of Cobalt:
Remember that a half-filled orbital is very stable, and when it is possible for an ion to have a
electron configuration it will. In order to attain this, two electrons will be removed from the
orbitals and one will be removed from the
orbital, yielding:
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