Q: What is the energy of a photon emitted when an electron in a hydrogen atom transitions from $$n=5 to$$ $$n=2$$? (Use $$E = -2.18 \times 10$$^{-18}$$\ \text{J} \left(\frac{1}{n_f^2$} - \frac{1}{n_i^2$}\right))$$

$$4.58 \times 10$$^{-19}$$\ \text{J}$$

Question 1

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

$$l$$

Question 2

What is the maximum number of electrons that can occupy the 3d subshell?

Accepted Answer

10

Question 3

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 4

An electron in a hydrogen atom drops from $$n=4 to$$ $$n=2. $$What happens as a result?

Accepted Answer

A photon is emitted

Question 5

Which of the following sets 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 6

Which orbital is spherical in shape?

Accepted Answer

1s

Question 7

What is the electron configuration for oxygen in its ground state?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^4$$

Question 8

Which statement best describes the difference between the ground state and an excited state of an atom?

Accepted Answer

The ground state has electrons in the lowest available energy levels, while the excited state has one or more electrons in higher energy levels.

Question 9

Which of the following best explains why sodium emits a yellow color in a flame test?

Accepted Answer

Electrons in sodium transition from higher to lower energy levels, emitting photons with energy corresponding to yellow light.

Question 10

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

Accepted Answer

$$m_l$$

Question 11

A cobalt atom has 27 electrons. What is the correct ground state electron configuration for cobalt?

Accepted Answer

$$[Ar]\ 4s^2$\ 3d^7$

Question 12

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

Accepted Answer

Hund's Rule

Question 13

What is the energy of a photon emitted when an electron in a hydrogen atom transitions from $$n=5 to$$ $$n=2$$? (Use $$E = -2.18 	imes 10$$^{-18}$$\ 	ext{J} \left(\frac{1}{n_f^2$} - \frac{1}{n_i^2$}ight))$$

Accepted Answer

$$4.58 	imes 10$$^{-19}$$\ 	ext{J}$$

Question 14

Which of the following is a valid set of quantum numbers for an electron in a 4p orbital?

Accepted Answer

$$n=4,\ l=1,\ m_l=0,\ m_s=+\frac{1}{2}$$

Question 15

Which of the following statements about the Heisenberg Uncertainty Principle is correct?

Accepted Answer

It states that there is a fundamental limit to how precisely both the position and momentum of an electron can be known simultaneously.

Question 16

Which of the following best describes the relationship between the periodic law and electron configuration?

Accepted Answer

The periodic law states that the properties of elements are a periodic function of their atomic numbers, which is reflected in their electron configurations.

Question 17

Which of the following is the correct noble gas shorthand electron configuration for selenium (Se, atomic number 34)?

Accepted Answer

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

Question 18

If an atom has the electron configuration $$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^6$$\ $$4s^2$$\ $$3d^{10}$$\ $$4p^5$$, what element is it?

Accepted Answer

Bromine (Br)

Question 19

Which of the following best describes the shape of a d orbital?

Accepted Answer

Cloverleaf-shaped

Question 20

A sample of hydrogen gas is excited with energy, and the emission spectrum is observed. Which of the following best explains why only certain wavelengths are observed?

Accepted Answer

Electrons can only occupy specific, quantized energy levels, so only certain transitions (and thus certain wavelengths) are possible.

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