5th-6th Grade Chapter 12 Test

Building blocks of all matter.

• cells

• atoms

• substances

• metals

The core or center of an atom.

• nucleus

• electron shell

• neutron

• proton

A particle in the nucleus with a positive charge.

• neutron

• electron

• proton

• atom

A particle in an atom with a negative charge.

• proton

• electron

• neutron

• nucleus

A particle in the nucleus with no charge.

• proton

• neutron

• electron

• atom

The _____ is the number of protons in the nucleus of an atom.

• atomic mass

• atomic number

• mass number

• period number

Area around the nucleus where electrons are found.

• nuclear shell

• electron shell

• proton shell

• all the above

Most atoms contain equal numbers of protons and _____.

• neutrons

• electrons

• atomic number

• proton shells

An atom that has lost an electron becomes _____ charged.

• negatively

• positively

• neutrally

• super

An atom that has gained an electron becomes _____ charged.

• positively

• neutrally

• super

• negatively