Module 2 Check Matter

A(n) _______________ represents the area in an atom where an electron is most likely to be found.

• orbital

• atomic mass

• energy level

• ion

• mass number

An atom that gains or loses an electron and has an electric charge is called a(n) _______________.

• energy level

• neutron

• mass number

• atomic mass

• ion

The combined number of protons and neutrons is the _______________.

• atomic number

• mass number

• ion

• atomic mass

• energy level

The _______________ is the average of the mass numbers of the isotopes of an element.

• atomic mass

• energy level

• ion

• mass number

How many electrons can be held in the innermost energy level of atoms?

• 2

• 8

• 18

• 32

Many elements are mixtures of

• isotopes.

• oxygen.

• electrons.

• neutrons.

The chemical behavior of different elements is determined by the

• number of electrons in the innermost energy level.

• total number of electrons in all of the energy levels.

• number of electrons in the outermost energy level.

• number of electrons in the middle energy level.