$\text{Mass Number} = \text{Number of Protons} + \text{Number of Neutrons}$

Question 1

Which of the following best describes how the periodic table is organized?

Accepted Answer

By increasing atomic number

Question 2

What is the primary reason elements in the same group (column) of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of valence electrons

Question 3

Which of the following equations correctly represents the relationship between the number of protons, neutrons, and the mass number of an atom?

Accepted Answer

$	ext{Mass Number} = 	ext{Number of Protons} + 	ext{Number of Neutrons}$

Question 4

Which statement best explains why atomic radius increases as you move down a group in the periodic table?

Accepted Answer

The number of energy levels (rings) increases

Question 5

What happens to the energy of an electron as it moves closer to the nucleus?

Accepted Answer

The energy decreases

Question 6

Which of the following best describes an ion?

Accepted Answer

An atom that has gained or lost electrons

Question 7

If an atom has 11 protons, 12 neutrons, and 10 electrons, what is its charge?

Accepted Answer

$+1$

Question 8

Which of the following elements would you expect to have the highest electronegativity?

Accepted Answer

Fluorine ($\mathrm{F}$)

Question 9

Which of the following best explains why elements in the same period (row) have different properties?

Accepted Answer

They have different numbers of valence electrons

Question 10

Which of the following is the correct electron configuration for a neutral oxygen atom ($Z=8$)?

Accepted Answer

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

Question 11

Which of the following best describes the trend in ionization energy across a period from left to right?

Accepted Answer

It increases

Question 12

A sodium atom ($\mathrm{Na}$) loses one electron to form a $\mathrm{Na}^+$ ion. Which of the following statements is true?

Accepted Answer

The $\mathrm{Na}^+$ ion has the same number of electrons as a neon atom

Question 13

Which of the following best explains why halogens are highly reactive?

Accepted Answer

They need only one more electron to achieve a stable octet

Question 14

Which of the following is the best definition of electronegativity?

Accepted Answer

The tendency of an atom to attract electrons in a chemical bond

Question 15

Which of the following best describes what happens when an electron absorbs energy?

Accepted Answer

It moves to a higher energy level (excited state)

Question 16

Which of the following is true about the maximum number of electrons in the second energy level (shell) of an atom?

Accepted Answer

$8$

Question 17

Which of the following best explains why elements with similar valence electron configurations have similar chemical reactivity?

Accepted Answer

They have similar tendencies to gain, lose, or share electrons

Question 18

Which of the following is the correct order of increasing atomic radius for the elements $\mathrm{F}$, $\mathrm{Cl}$, and $\mathrm{Br}$?

Accepted Answer

$\mathrm{F} < \mathrm{Cl} < \mathrm{Br}$

Question 19

Which of the following best describes the movement of electrons when an atom emits light?

Accepted Answer

Electrons move from a higher to a lower energy level

Question 20

Which of the following statements about transition metals is correct?

Accepted Answer

They often form ions with multiple possible charges

Study Guide: Electrons and the Periodic Table

Study Guide - Practice Questions