Q: A sodium lamp emits yellow light with a wavelength of $$589\ \mathrm{nm}. $$What is the energy of a single photon of this light? $$(h = 6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s},\ c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$3.38 \times 10$$^{-19}$$\ \mathrm{J}$$

Q: A photon with energy $$4.0 \times 10$$^{-19}$$\ \mathrm{J}$$ strikes a metal surface with a work function of $$2.5 \times 10$$^{-19}$$\ \mathrm{J}. $$What is the maximum kinetic energy of the emitted electron?

$$1.5 \times 10$$^{-19}$$\ \mathrm{J}$$

Question 1

Which of the following statements best explains why the first ionization energy of nitrogen is higher than that of oxygen, despite oxygen being to the right of nitrogen in the periodic table?

Accepted Answer

Nitrogen has a half-filled p subshell, which is more stable and requires more energy to remove an electron.

Question 2

A sodium lamp emits yellow light with a wavelength of $$589\ \mathrm{nm}. $$What is the energy of a single photon of this light? $$(h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s},\ c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$3.38 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 3

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

Accepted Answer

$$\mathrm{Ca$$^{2+}$$}$$

Question 4

Which of the following best describes the effect of increasing the intensity of light in the photoelectric effect experiment, while keeping the frequency below the threshold frequency?

Accepted Answer

No electrons are ejected, regardless of the intensity.

Question 5

Which of the following electron configurations represents the ground state of a neutral chromium atom?

Accepted Answer

$$[\mathrm{Ar}]\ 3d^5$\ 4s^1$

Question 6

What is the molecular geometry and approximate bond angle of $$\mathrm{SO_2$}$$ according to VSEPR theory?

Accepted Answer

Bent, less than $$120^\circ$$

Question 7

Which of the following statements about the de Broglie wavelength is correct?

Accepted Answer

A faster-moving electron has a shorter de Broglie wavelength.

Question 8

Which of the following compounds contains both ionic and covalent bonds?

Accepted Answer

$$\mathrm{NH_4Cl}$$

Question 9

How many radial nodes are present in a $$3p$$ orbital?

Accepted Answer

1

Question 10

Which of the following best explains why the lattice energy of $$\mathrm{MgO} is $$much greater in magnitude than that of $$\mathrm{NaF}$$?

Accepted Answer

$$\mathrm{MgO}$$ has ions with higher charges and smaller radii, leading to stronger electrostatic attraction.

Question 11

Which of the following molecules is nonpolar, despite having polar bonds?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 12

What is the correct formula for iron(III) sulfate?

Accepted Answer

$$\mathrm{Fe_2$(SO_4$)_3}$$

Question 13

A photon with energy $$4.0 	imes 10$$^{-19}$$\ \mathrm{J}$$ strikes a metal surface with a work function of $$2.5 	imes 10$$^{-19}$$\ \mathrm{J}. $$What is the maximum kinetic energy of the emitted electron?

Accepted Answer

$$1.5 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 14

Which set of quantum numbers is not allowed for an electron in an atom?

Accepted Answer

$$n = 2,\ l = 2,\ m_l = 0,\ m_s = +\frac{1}{2}$$

Question 15

Which of the following best describes the electron configuration of $$\mathrm{Fe$$^{3+}$$}$$?

Accepted Answer

$$[\mathrm{Ar}]\ 3d^5$

Question 16

Which of the following statements about resonance structures is correct?

Accepted Answer

The actual molecule is a resonance hybrid, with delocalized electrons.

Question 17

What is the formal charge on the central atom in the best Lewis structure for $$\mathrm{NO_3$^-}$$?

Accepted Answer

0

Question 18

Which of the following molecules has a square planar molecular geometry?

Accepted Answer

$$\mathrm{$$XeF_4$$}$$

Question 19

Which of the following best explains why the second ionization energy of sodium is much greater than the first?

Accepted Answer

The second electron is removed from a stable, closed-shell configuration.

Question 20

Which of the following statements about the relationship between wavelength, frequency, and photon energy is correct?

Accepted Answer

Shorter wavelength corresponds to higher frequency and higher photon energy.

General Chemistry I: Core Concepts and Memorization Guide

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