Chemistry Review

The subatomic particles are called:

• protons, nucleus and electrons

• protons, electrons and neutrons

• protons, positives and negatives

• cloud, shell and quarks

Substances that have only one kind of atom are called:

• elements

• compounds

• molecules

• ions

Why do the electrons surround the nucleus?

• the negative electrons are attracted to the neutral neutrons

• the negative electrons are repelled by the neutral neutrons

• the negative electrons are attracted to the positive protons

• the negative electrons are repelled by the positive protons

The _____ is based on the number of protons in the nucleus of the atom.

• atomic structure

• periodic table of the elements

• atomic number

• atomic mass

What is the mass number of this atom?

• 1

• 3

• 4

• 7

What is the atomic number of Barium, Ba? (enlarge the periodic table)

• 20

• 38

• 56

• 88

Atoms of the same element which have a different number of neutrons are called _________________.

• ions

• isotopes

• neutrons

• molecules

How many neutrons does C-14 contain? (tap to enlarge the image)

• 6

• 7

• 14

• 8

If X is the symbol for an element, which of the following two symbols represent    isotopes of the same element?     I. ⁷⁷₃₅X  II. ⁷⁷₃₃X  III. ⁸¹₃₇X  IV. ⁸¹₃₅ X

• I and II

• III and IV

• I and IV

• I and III

Calculate the average atomic mass of silver.

• 106.38649 amu

• 111.91896 amu

• 107.8677 amu

• 121 amu