Category 1 & 2 Review

the tiny particles that make up an atom; proton, neutron and electron.

• atom
• electron cloud
• nucleus
• subatomic particles

the positively charged particle that is found in an atom's nucleus.

• subatomic particle
• proton
• neutron
• electron

the neutral particle that is found in the atom's nucleus.

• neutron
• proton
• electron
• nucleus

the negatively charged particle that is found in the atom's electron cloud.

• electron
• proton
• neutron
• nucleus

the central area of the atom that contains the protons and neutrons.

• nucleus
• proton
• electron
• neutron

the electron(s) found in the outermost electron shell (ring) that determines an atom's reactivity.

• valence electron
• proton
• neutron
• electron

building block of all matter

• atom
• proton
• neutron
• electron

the area outside the nucleus that contains the electrons

• electron cloud
• electron
• nucleus
• subatomic particle

the sum of protons and neutrons that determines an atom's mass

• atomic mass
• atomic number
• nucleus
• neutron

the number that identifies an element; indicates the number of protons

• atomic number
• atomic mass
• proton number
• electron number