Question 1

The effective nuclear charge for an atom is less than the actual nuclear charge due to

Accepted Answer

Shielding is the phenomenon where electrons in outer energy levels of an atom are partially shielded from the full nuclear charge by electrons in inner energy levels. This results in a decreased effective nuclear charge experienced by the outer electrons.

Question 2

Select the correct electron configuration for Cu (Z = 29).

Accepted Answer

The correct electron configuration for Cu (Z = 29) is [Ar] 3d^10 4s^1, which corresponds to the choice that indicates a full 3d subshell (10 electrons) and a single electron in the 4s subshell.

Question 3

Select the correct set of quantum numbers (n, l, m_l, m_s) for the first electron removed in the formation of a cation for strontium, Sr.

Accepted Answer

Strontium (Sr) has an electron configuration ending in 5s^2. The first electron removed during cation formation comes from the outermost shell, which is the 5s orbital. The quantum numbers for an electron in the 5s orbital are n=5 (principal quantum number), l=0 (azimuthal quantum number for an s orbital), m_l=0 (magnetic quantum number, which is 0 for s orbitals), and m_s can be either +½ or −½ (spin quantum number). Option E correctly represents these quantum numbers for the first electron removed.

Question 4

Select the correct electron configuration for Te (Z = 52).

Accepted Answer

Tellurium (Te) has an atomic number of 52. Its electron configuration is [Kr]5s²4d¹⁰5p⁴, which corresponds to option E.

Question 5

Which of the following electron configurations is impossible?

Accepted Answer

The electron configuration 1s²2s²2p⁶3s³3p⁴ is impossible because it violates the Aufbau principle. The Aufbau principle states that electrons fill orbitals in order of increasing energy. The 3s orbital has a higher energy than the 3p orbital, so the 3s orbital should be filled before the 3p orbital.

Question 6

Which of the following sublevels is filled last? 3d, 4s, 4p, 4d, 5s

Accepted Answer

According to the Aufbau principle, electrons fill orbitals starting from the lowest-energy level to the highest. Within the same energy level, the sublevels fill in the order: s, p, d, f. However, for elements in the fourth and higher periods of the periodic table, the 3d sublevel (which has slightly higher energy than the 4s sublevel) fills after the 4s sublevel. Therefore, the 4d sublevel is filled after the 4s sublevel, making choice D the correct answer.

Question 7

How many valence electrons are there in an atom with the electron configuration [noble gas]ns²(n −1)d¹⁰np³?

Accepted Answer

The valence electrons are the electrons in the outermost shell, which in this case are the ns and np electrons. Therefore, there are 2 (from ns) + 3 (from np) = 5 valence electrons.

Question 8

In a single atom, what is the maximum number of electrons which can have quantum number n = 4?

Accepted Answer

The maximum number of electrons in a shell is given by 2n^2. For n = 4, it is 2*(4^2) = 2*16 = 32.

Question 9

"Electrons added to atomic orbitals of the same energy will remain unpaired with parallel spins until the subshell is more than half-filled" is a statement of

Accepted Answer

This statement is a restatement of Hund's rule, which states that electrons will occupy unpaired orbitals of the same energy level with parallel spins before they begin to pair up. This is because the electrostatic repulsion between electrons in the same orbital is minimized when their spins are parallel. Once all the orbitals of a subshell are half-filled, the repulsion between electrons is greater than the repulsion between electrons and the nucleus, and the electrons begin to pair up.

Question 10

Which one of the following statements about atomic structure and quantum numbers is incorrect?

Accepted Answer

The quantum number m_l only goes from -l to +l for a given subshell, so for n=4 and l=3, the largest possible value of m_l would be -3, -2, -1, 0, 1, 2, or 3.

Question 11

In the ground state of an atom of silver (Ag), how many electrons will there be with the quantum number l = 1? (The n, m_l, and m_s quantum numbers may have any appropriate values.)

Accepted Answer

In the ground state of silver (Ag), which has an atomic number of 47, the electron configuration is [Kr] 4d^10 5s^1. Electrons with l = 1 are in p orbitals. The filled p orbitals are 2p^6, 3p^6, and 4p^6, totaling 18 electrons.

Question 12

An atom of element number 33 (As) is in its ground electronic state. Which one of the following sets quantum numbers could not apply to any of its electrons?

Accepted Answer

Arsenic (As) has an electron configuration of [Ar] 3d¹⁰ 4s² 4p³. The quantum numbers in option E correspond to an electron in the 4d subshell, which does not exist in the ground state configuration of arsenic.

Question 13

In many-electron atoms, which quantum numbers specify the energy of an electron?

Accepted Answer

The energy of an electron in a many-electron atom is primarily determined by the principal quantum number (n) and the azimuthal (or angular momentum) quantum number (l). These two quantum numbers define the energy level and sublevel of an electron, respectively.

Question 14

The electronic structure 1s²2s²2p⁶3s²3p⁶4s²3d⁸refers to the ground state of

Accepted Answer

The electronic configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸ corresponds to Nickel (Ni), which has an atomic number of 28.

Question 15

Select the correct set of quantum numbers (n, l, m_l, m_s) for the highest energy electron in the ground state of tin, Sn.

Accepted Answer

The highest energy electron in the ground state of tin has the following quantum numbers: n = 5, l = 1, m_l = 0, and m_s = ½. This is because the highest energy electron is in the 5p orbital, which has n = 5 and l = 1. The m_l value of 0 indicates that the electron is in the p_z orbital, and the m_s value of ½ indicates that the electron has a spin of +½.

Question 16

Which of the following sets of elements have the [noble gas]ns²np² valence electron configuration?

Accepted Answer

The elements in option D (C, Si, Ge, Sn, Pb) belong to group 14 of the periodic table and have the valence electron configuration [noble gas]ns²np².

Question 17

How many valence electrons are there in an atom with the electron configuration [noble gas]ns²(n − 1)d⁸?

Accepted Answer

The answer of How many valence electrons are there in...

Question 18

Select the correct set of quantum numbers (n, l, m_l, m_s) for the highest energy electron in the ground state of potassium, K.

Accepted Answer

The highest energy electron in potassium (K) in its ground state is in the 4s orbital, which corresponds to quantum numbers n=4, l=0, m_l=0, m_s=½.

Question 19

Which of the following electron configurations represents the ground state of an element?

Accepted Answer

The correct electron configuration for a ground state element follows the Aufbau principle, Hund's rule, and the Pauli exclusion principle. Option E correctly represents the ground state electron configuration for an element following these rules, starting with the [Ne] core and filling the 3s and 3p orbitals in accordance with these principles.

Question 20

Select the correct electron configuration for sulfur (Z = 16).

Accepted Answer

Sulfur has 16 electrons, and its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁴.

Quiz 8: Electron Configuration and Chemical Periodicity

The effective nuclear charge for an atom is less than the actual nuclear charge due to

Select the correct electron configuration for Cu (Z = 29) .

Select the correct set of quantum numbers (n, l, m_l, m_s) for the first electron removed in the formation of a cation for strontium, Sr.

Select the correct electron configuration for Te (Z = 52) .

Which of the following electron configurations is impossible?

Which of the following sublevels is filled last? 3d, 4s, 4p, 4d, 5s

How many valence electrons are there in an atom with the electron configuration [noble gas]ns²(n −1) d¹⁰np³?

In a single atom, what is the maximum number of electrons which can have quantum number n = 4?

"Electrons added to atomic orbitals of the same energy will remain unpaired with parallel spins until the subshell is more than half-filled" is a statement of

Which one of the following statements about atomic structure and quantum numbers is incorrect?

In the ground state of an atom of silver (Ag) , how many electrons will there be with the quantum number l = 1? (The n, m_l, and m_s quantum numbers may have any appropriate values.)

An atom of element number 33 (As) is in its ground electronic state. Which one of the following sets quantum numbers could not apply to any of its electrons?

In many-electron atoms, which quantum numbers specify the energy of an electron?

The electronic structure 1s²2s²2p⁶3s²3p⁶4s²3d⁸refers to the ground state of

Select the correct set of quantum numbers (n, l, m_l, m_s) for the highest energy electron in the ground state of tin, Sn.

Which of the following sets of elements have the [noble gas]ns²np² valence electron configuration?

How many valence electrons are there in an atom with the electron configuration [noble gas]ns²(n − 1) d⁸?

Select the correct set of quantum numbers (n, l, m_l, m_s) for the highest energy electron in the ground state of potassium, K.

Which of the following electron configurations represents the ground state of an element?

Select the correct electron configuration for sulfur (Z = 16) .

Quiz 8: Electron Configuration and Chemical Periodicity

The effective nuclear charge for an atom is less than the actual nuclear charge due to

Select the correct electron configuration for Cu (Z = 29) .

Select the correct set of quantum numbers (n, l, ml, ms) for the first electron removed in the formation of a cation for strontium, Sr.

Select the correct electron configuration for Te (Z = 52) .

Which of the following electron configurations is impossible?

Which of the following sublevels is filled last? 3d, 4s, 4p, 4d, 5s

How many valence electrons are there in an atom with the electron configuration [noble gas]ns2(n −1) d10np3?

In a single atom, what is the maximum number of electrons which can have quantum number n = 4?

"Electrons added to atomic orbitals of the same energy will remain unpaired with parallel spins until the subshell is more than half-filled" is a statement of

Which one of the following statements about atomic structure and quantum numbers is incorrect?

In the ground state of an atom of silver (Ag) , how many electrons will there be with the quantum number l = 1? (The n, ml, and ms quantum numbers may have any appropriate values.)

An atom of element number 33 (As) is in its ground electronic state. Which one of the following sets quantum numbers could not apply to any of its electrons?

In many-electron atoms, which quantum numbers specify the energy of an electron?

The electronic structure 1s22s22p63s23p64s23d8 refers to the ground state of

Select the correct set of quantum numbers (n, l, ml, ms) for the highest energy electron in the ground state of tin, Sn.

Which of the following sets of elements have the [noble gas]ns2np2 valence electron configuration?

How many valence electrons are there in an atom with the electron configuration [noble gas]ns2(n − 1) d8?

Select the correct set of quantum numbers (n, l, ml, ms) for the highest energy electron in the ground state of potassium, K.

Which of the following electron configurations represents the ground state of an element?

Select the correct electron configuration for sulfur (Z = 16) .

Select the correct set of quantum numbers (n, l, m_l, m_s) for the first electron removed in the formation of a cation for strontium, Sr.

How many valence electrons are there in an atom with the electron configuration [noble gas]ns²(n −1) d¹⁰np³?

In the ground state of an atom of silver (Ag) , how many electrons will there be with the quantum number l = 1? (The n, m_l, and m_s quantum numbers may have any appropriate values.)

The electronic structure 1s²2s²2p⁶3s²3p⁶4s²3d⁸refers to the ground state of

Select the correct set of quantum numbers (n, l, m_l, m_s) for the highest energy electron in the ground state of tin, Sn.

Which of the following sets of elements have the [noble gas]ns²np² valence electron configuration?

How many valence electrons are there in an atom with the electron configuration [noble gas]ns²(n − 1) d⁸?

Select the correct set of quantum numbers (n, l, m_l, m_s) for the highest energy electron in the ground state of potassium, K.