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 (Br) has an atomic number of 35 and a mass number of 80. How many neutrons does it contain?

Accepted Answer

$$80 - 35 = 45$$ neutrons

Question 3

Which element is most likely to have chemical properties similar to krypton (Kr)?

Accepted Answer

Neon (Ne)

Question 4

Which of the following lists contains only alkali metals?

Accepted Answer

Li, Na, K

Question 5

Which property is NOT characteristic of metals?

Accepted Answer

Powdery solids or gases

Question 6

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

Accepted Answer

3

Question 7

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

Accepted Answer

Aluminum (Al)

Question 8

What is the total number of electrons in a neutral atom of calcium (Ca, atomic number 20)?

Accepted Answer

20

Question 9

Which group on the periodic table contains the least reactive elements?

Accepted Answer

Group 8A (Noble gases)

Question 10

A neutral atom of selenium (Se, atomic number 34) is found in which group and period?

Accepted Answer

Group 6A, Period 4

Question 11

Which of the following best explains why chlorine (Cl) forms a $$-1$$ ion?

Accepted Answer

Chlorine gains one electron to achieve the electron configuration of the nearest noble gas.

Question 12

Which of the following is a property of metalloids?

Accepted Answer

They conduct electricity moderately well.

Question 13

If an atom has 17 protons, 18 neutrons, and 17 electrons, what is its mass number?

Accepted Answer

$$17 + 18 = 35$$

Question 14

Which of the following elements is a nonmetal?

Accepted Answer

Oxygen (O)

Question 15

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their outer shell.

Question 16

A cation is formed when an atom:

Accepted Answer

Loses one or more electrons

Question 17

Which of the following elements is a metalloid?

Accepted Answer

Silicon (Si)

Question 18

Which of the following elements is in Group 2A and Period 4?

Accepted Answer

Calcium (Ca)

Question 19

Which of the following best describes the electron configuration of an $$O^{2-}$$ ion?

Accepted Answer

It has the same electron configuration as neon (Ne).

Question 20

Which of the following lists contains only metals?

Accepted Answer

Mg, Ca, Na

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

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