4.1.2 - Mass & Atomic Number, Isotopes

What do all forms of the same element have in common?

They all have the same number of protons.

What is the name given to the number of protons in an atom?

atomic number

What is an atom’s mass number?

The total number of protons and neutrons in the atom.

What is an isotopes of an atom?

An atom of an element that has a different number of neutrons, but the same number of protons.

How do atoms turn into positive ions?

• They lose one or more of their outer electrons.

• Electrons are negatively charged, so the resultant charge of the atom is positive.