Atomic #/mass #

The atomic number tells you

• the number of protons

• the number of neutrons

• the number of electrons

• charge of the nucleus

• mass of the atom

The mass number is determined by the

• number of protons + neutrons

• number of protons + electrons

• number of neutrons + electrons

• number of electrons

Symbol of iron.

Number of protons in nitrogen.

Number of electrons in oxygen

The number of neutrons in F

The name of Cu

An atom has 45 protons. How many electrons must it have?

How many neutrons in a iodine atom?

What unit is used for the mass number of an atom?

• g

• atomic mass unit

• u

• grams

• mg