Question 1

Which of the following statements best describes the periodic law?

Accepted Answer

The physical and chemical properties of the elements are periodic functions of their atomic numbers.

Question 2

An atom of bromine ($$^{80}_{35}\mathrm{Br}) $$has how many neutrons?

Accepted Answer

$$45$$ neutrons

Question 3

Which group and period does selenium (Se, atomic number 34) belong to?

Accepted Answer

Group 6A, Period 4

Question 4

Which of the following elements is most likely to have chemical properties similar to krypton (Kr)?

Accepted Answer

Ne

Question 5

Which of the following lists contains only alkali metals?

Accepted Answer

Li, Na, K

Question 6

Which of the following is a property of metals?

Accepted Answer

High electrical conductivity

Question 7

How many valence electrons does an atom of aluminum (Al) have?

Accepted Answer

$$3$$

Question 8

According to the octet rule, how will sodium (Na) achieve a stable electron configuration?

Accepted Answer

By losing one electron

Question 9

Which of the following elements will form an ion with a charge of $$+3$$?

Accepted Answer

Al

Question 10

What is the electron configuration of the oxide ion ($$\mathrm{O}^{2-}$$)?

Accepted Answer

$$[He]2s^2$ 2p^6$

Question 11

Which of the following lists contains only metals?

Accepted Answer

Li, Na, K

Question 12

A cation is formed when an atom:

Accepted Answer

Loses electrons

Question 13

Which of the following best describes a metalloid?

Accepted Answer

A brittle solid that conducts electricity moderately well

Question 14

Which element is in Group 2A and Period 4?

Accepted Answer

Ca

Question 15

Which of the following elements is a halogen?

Accepted Answer

Cl

Question 16

If an atom has 20 protons, 20 neutrons, and 20 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number = 20, Mass number = 40

Question 17

Which of the following is a property of nonmetals?

Accepted Answer

Powdery solids or gases

Question 18

Which group contains the least reactive elements?

Accepted Answer

Group 8A

Question 19

Which of the following elements is a main group element?

Accepted Answer

Na

Question 20

A neutral atom of barium (Ba, atomic number 56) has how many electrons?

Accepted Answer

$$56$$

Atoms, Elements, and the Periodic Table: Study Guide for General Chemistry

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