Question 1

Which of the following is the correct ground state electron configuration for the fluoride ion (F⁻)?

Accepted Answer

$1s^2\ 2s^2\ 2p^6$

Question 2

Which quantum numbers describe a 2p orbital in a fluorine atom?

Accepted Answer

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

Question 3

Which element has the excited state electron configuration $1s^2\ 2s^2\ 2p^6\ 3p^1$?

Accepted Answer

Sodium

Question 4

What is the condensed electron configuration for $V^{2+}$?

Accepted Answer

$[Ar]\ 3d^3$

Question 5

Which of the following atoms has the largest effective nuclear charge ($Z_{eff}$) felt by its 2p electrons?

Accepted Answer

Bromine

Question 6

Why does atomic radius generally decrease from left to right across a period?

Accepted Answer

Because the effective nuclear charge ($Z_{eff}$) increases, pulling electrons closer

Question 7

Which of the following ions is most difficult to remove an additional electron from, based on $Z_{eff}$ and principal quantum number?

Accepted Answer

Na$^+$

Question 8

What is the maximum likely charge of a vanadium ion formed from the ground state configuration $[Ar]\ 4s^2\ 3d^3$?

Accepted Answer

+1 or +2

Question 9

Which statement best explains why oxygen has a smaller atomic radius than sulfur?

Accepted Answer

Oxygen has a higher $Z_{eff}$ and its valence electrons are closer to the nucleus

Question 10

When an electron in sodium moves from the 3s orbital to the 3p orbital, what happens to the energy of the atom?

Accepted Answer

Energy is absorbed

Question 11

Which of the following box diagrams correctly represents the valence shell of $N^{3-}$?

Accepted Answer

2s: $\uparrow\downarrow$; 2p: $\uparrow\downarrow\ \uparrow\downarrow\ \uparrow\downarrow$

Question 12

Which of the following best describes the shielding effect in atoms?

Accepted Answer

Inner electrons shield outer electrons from the full nuclear charge

Question 13

Which electron configuration represents an atom in its ground state?

Accepted Answer

$1s^2\ 2s^2\ 2p^6\ 3s^1$

Question 14

Which of the following statements about $Z_{eff}$ is correct?

Accepted Answer

$Z_{eff}$ increases as you move left to right across a period

Question 15

Which orbital is filled after $3p$ in the Aufbau principle?

Accepted Answer

$4s$

Question 16

If an atom has the electron configuration $[Ar]\ 4s^2\ 3d^1$, what is the element?

Accepted Answer

Scandium

Question 17

Which of the following best explains why the 2p electrons in bromine feel the largest $Z_{eff}$ compared to P, Cl, and As?

Accepted Answer

Bromine has the most protons and the same shielding by 1s electrons

Question 18

Which of the following is a correct statement about the removal of electrons from transition metals?

Accepted Answer

Electrons are removed from the highest energy orbital, usually 4s, before 3d

Question 19

Which of the following elements has the smallest atomic radius?

Accepted Answer

Oxygen

Atomic Structure, Electron Configuration, and Periodic Trends: Study Notes

Study Guide - Practice Questions