Question 1

Which of the following best describes the photoelectric effect as observed by Einstein?

Accepted Answer

Electrons are emitted from a metal surface only when the incident light has a frequency above a certain threshold, regardless of the light's intensity.

Question 2

What does it mean when we say that the energies of electrons in an atom are quantized?

Accepted Answer

Electrons can only occupy specific energy levels, and cannot exist between these levels.

Question 3

Which of the following is the correct ground state electron configuration for Zn using noble gas core notation?

Accepted Answer

$$[\mathrm{Ar}]\ 4s^2$\ 3d$$^{10}$$

Question 4

Which of the following best explains what happens inside an atom when it emits light?

Accepted Answer

An electron transitions from a higher energy level to a lower energy level, releasing a photon.

Question 5

Assign all four quantum numbers to a valence electron in the ground state of argon ($$Z=18). $$Which set is correct?

Accepted Answer

$$n=3,\ l=1,\ m_l=1,\ m_s=+\frac{1}{2}$$

Question 6

Which of the following ions is isoelectronic with argon and has the smallest atomic radius?

Accepted Answer

$$\mathrm{Al}^{3+}$$

Question 7

Which of the following atoms or ions is paramagnetic?

Accepted Answer

Aluminum atom ($$\mathrm{Al})$$

Question 8

Which atom has the higher first ionization energy, potassium ($$\mathrm{K}) or $$lithium ($$\mathrm{Li}$$), and why?

Accepted Answer

$$\mathrm{Li}$$, because its valence electron is closer to the nucleus and experiences a stronger effective nuclear charge.

Question 9

Which of the following pairs has the larger atomic radius, and why? $$\mathrm{Na} or$$ $$\mathrm{P}$$

Accepted Answer

$$\mathrm{Na}$$, because it has fewer protons and less effective nuclear charge pulling the electrons inward.

Question 10

Which of the following best describes why the second electron affinity of oxygen is endothermic?

Accepted Answer

Adding a second electron to an already negatively charged ion requires energy to overcome electron-electron repulsion.

Question 11

Which of the following molecules is non-polar overall?

Accepted Answer

$$\mathrm{CCl}_4$$

Question 12

What is the hybridization of the central atom in $$\mathrm{ClF}_2^+$$?

Accepted Answer

$$sp^3$$

Question 13

Which statement about $$\mathrm{N}_2 is $$FALSE?

Accepted Answer

The oxidation number is +3 on one N and -3 on the other.

Question 14

Which of the following best explains why $$\mathrm{Na}^+ is $$smaller than $$\mathrm{Na}$$?

Accepted Answer

$$\mathrm{Na}^+$$ has lost its outermost electron shell, resulting in a smaller radius.

Question 15

Which of the following has the largest first ionization energy?

Accepted Answer

Nitrogen ($$\mathrm{N})$$

Question 16

Which of the following best describes the molecular geometry of $$\mathrm{XeF}_2$$?

Accepted Answer

Linear, with 5 electron pairs around Xe

Question 17

Which of the following best describes the difference between the Bohr model and the quantum mechanical model of the atom?

Accepted Answer

The Bohr model describes electrons in fixed orbits, while the quantum mechanical model describes electrons as existing in probability clouds (orbitals).

Question 18

Which of the following best explains why metals tend to lose electrons and non-metals tend to gain electrons?

Accepted Answer

Metals have low ionization energies and large atomic radii, making it easier to lose electrons, while non-metals have high ionization energies and small atomic radii, favoring electron gain.

Question 19

Calculate the wavelength (in nm) of electromagnetic radiation with a frequency of $$6.00 	imes 10$$^{14}$$\ \mathrm{Hz}$$. ($$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$500\ \mathrm{nm}$$

Question 20

Which of the following best describes a sigma ($$\sigma) $$bond?

Accepted Answer

A bond formed by the head-on overlap of atomic orbitals along the internuclear axis.

General Chemistry II Exam 2 Review – Step-by-Step Study Guidance

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