Atom, Elements, and the Periodic Table

The number of protons in an atom is the __________.

• Mass number

• Atomic number

• Atomic mass

Elements arranged in vertical columns (up and down) are called __________.

• Groups/Families

• Periods

Atoms of the same element that have different numbers of neutrons are called __________.

• Compounds

• Molecules

• Isotopes

The particle with a negative charge is the __________.

• Proton

• Neutron

• Electron

Protons and neutrons are located in the __________ of an atom.

• Nucleus

• Electron cloud

The particle with a positive charge is the __________.

• Proton

• Neutron

• Electron

The particle with a neutral (no charge) is the __________.

• Proton

• Neutron

• Electron

Elements arranged in horizontal rows (across) are called __________.

• Groups/Families

• Periods

The __________ is the number of protons and neutrons in an atom.

• Mass number

• Atomic number

• Atomic mass

The part of the atom where the electrons are located is called the _________.

• Nucleus

• Electron cloud