Q: According to the Bohr model, what is the energy of an electron in the $n$th shell of a hydrogen atom?

$E_n = -2.178 \times 10^{-18} \left( \frac{Z^2}{n^2} \right) \, \text{J/atom}$

Q: A sodium atom requires $496 \, \text{kJ/mol}$ to be ionized. What is the lowest frequency of light that can ionize a sodium atom? $(h = 6.626 \times 10^{-34} \, \text{J} \cdot \text{s}, \, N_A = 6.022 \times 10^{23} \, \text{mol}^{-1})$

$\nu = 1.24 \times 10^{15} \, \text{Hz}$

Question 1

Which experiment provided the first conclusive evidence that light behaves as a wave?

Accepted Answer

Young's double-slit experiment

Question 2

According to the Bohr model, what is the energy of an electron in the $n$th shell of a hydrogen atom?

Accepted Answer

$E_n = -2.178 	imes 10^{-18} \left( \frac{Z^2}{n^2} ight) \, 	ext{J/atom}$

Question 3

Which of the following statements best explains why electrons do not spiral into the nucleus according to quantum mechanics?

Accepted Answer

Electrons occupy quantized energy levels and cannot lose energy continuously.

Question 4

What is the relationship between wavelength $(\lambda)$ and frequency $(
u)$ for electromagnetic radiation?

Accepted Answer

$\lambda 
u = c$

Question 5

A sodium atom requires $496 \, 	ext{kJ/mol}$ to be ionized. What is the lowest frequency of light that can ionize a sodium atom? $(h = 6.626 	imes 10^{-34} \, 	ext{J} \cdot 	ext{s}, \, N_A = 6.022 	imes 10^{23} \, 	ext{mol}^{-1})$

Accepted Answer

$
u = 1.24 	imes 10^{15} \, 	ext{Hz}$

Question 6

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number $(\ell)$

Question 7

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

Accepted Answer

$n=2, \ell=2, m_\ell=0, m_s=+\frac{1}{2}$

Question 8

Which principle states that no two electrons in an atom can have the same set of four quantum numbers?

Accepted Answer

Pauli Exclusion Principle

Question 9

What is the effect of increasing the atomic number across a period on the atomic radius?

Accepted Answer

Atomic radius decreases due to increased effective nuclear charge.

Question 10

Which of the following best describes the outcome of the Rutherford gold foil experiment?

Accepted Answer

Most alpha particles passed through, but a few were deflected at large angles, indicating a small, dense nucleus.

Question 11

Which equation correctly expresses the energy of a photon in terms of its frequency?

Accepted Answer

$E = h 
u$

Question 12

What is the main reason why the photoelectric effect could not be explained by classical physics?

Accepted Answer

Classical physics predicted that increasing light intensity would always eject electrons, regardless of frequency.

Question 13

Which of the following best describes Hund's Rule?

Accepted Answer

Electrons occupy degenerate orbitals singly before pairing.

Question 14

Which of the following is a consequence of the Heisenberg Uncertainty Principle?

Accepted Answer

It is impossible to know both the exact position and momentum of an electron simultaneously.

Question 15

Which of the following best explains why the emission spectrum of hydrogen contains only specific wavelengths?

Accepted Answer

Electrons can only occupy certain quantized energy levels.

Question 16

Which of the following is the correct Rydberg equation for predicting the wavelength of hydrogen emission lines?

Accepted Answer

$\frac{1}{\lambda} = R \left( \frac{1}{n_f^2} - \frac{1}{n_i^2} \right)$

Question 17

Which of the following statements about the Aufbau Principle is correct?

Accepted Answer

Electrons fill orbitals in order of increasing energy.

Question 18

Which of the following best describes the effect of electron shielding in multi-electron atoms?

Accepted Answer

Shielding decreases the effective nuclear charge experienced by outer electrons.

Question 19

Which property of metals is explained by their tendency to lose electrons and form basic oxides in water?

Accepted Answer

Metallic behavior

Atomic Structure, Waves, and Quantum Theory: Foundations of General Chemistry

Study Guide - Practice Questions

Study Guide - Flashcards