Question 1

Which of the following combinations of quantum numbers is NOT allowed for an electron in an atom?

Accepted Answer

$n = 2$, $l = 2$, $m = 1$

Question 2

Which of the following sublevel designations does NOT exist according to quantum mechanics?

Accepted Answer

7d

Question 3

As you move from left to right across a period in the periodic table, what happens to the ionization energy?

Accepted Answer

It increases

Question 4

How many electrons can fit in the 6th shell ($n = 6$) of an atom?

Accepted Answer

72

Question 5

How many nodes does a 5f orbital have?

Accepted Answer

4

Question 6

How many core electrons does an arsenic atom have?

Accepted Answer

28

Question 7

Which statement best describes the Pauli Exclusion Principle?

Accepted Answer

No two electrons in an atom can have the same set of four quantum numbers.

Question 8

Which of the following best defines electron affinity?

Accepted Answer

The energy change when an atom gains an electron to form a negative ion.

Question 9

What is the electron configuration of Mn (manganese)?

Accepted Answer

$[Ar]\ 4s^2\ 3d^5$

Question 10

What is the electron configuration for $Ba^{2+}$ (barium ion)?

Accepted Answer

$[Xe]$

Question 11

Which of the following is the correct electron configuration for a neutral lead atom ($Pb$)?

Accepted Answer

$[Xe]\ 4f^{14}\ 5d^{10}\ 6s^2\ 6p^2$

Question 12

Which quantum number determines the shape of an orbital?

Accepted Answer

Azimuthal quantum number ($l$)

Question 13

Which of the following elements has the highest electron affinity?

Accepted Answer

Chlorine

Question 14

If an atom has $n = 3$, what is the maximum number of electrons it can hold?

Accepted Answer

18

Question 15

Which of the following is a valid set of quantum numbers for an electron in a 3d orbital?

Accepted Answer

$n = 3$, $l = 2$, $m = 1$

Question 16

Which principle explains why electrons fill the lowest energy orbitals first?

Accepted Answer

Aufbau Principle

Question 17

Which of the following statements about core electrons is TRUE?

Accepted Answer

Core electrons are not involved in chemical bonding.

Question 18

Which orbital designation is NOT possible?

Accepted Answer

2d

Question 19

Which quantum number specifies the orientation of an orbital in space?

Accepted Answer

Magnetic quantum number ($m$)

Question 20

Which rule states that electrons will fill degenerate orbitals singly before pairing up?

Accepted Answer

Hund's Rule

Quantum Numbers, Electron Configuration, and Periodic Trends: Study Notes for Introductory Chemistry

Study Guide - Practice Questions