Atomic & Mass Number (OCR GCSE Physics A, Combined (Gateway Science Suite)): Flashcards

The number of protons in an atom

The same number of protons

Number of electrons = number of protons

Number of protons + number of neutrons

Atoms of the same element with different numbers of neutrons

Same atomic (proton) number

Different mass numbers (different neutrons)

$\text{neutrons} = \text{mass number} - \text{atomic number}$

Process where atoms lose or gain electrons

Atoms that have lost or gained electrons

When they have lost electrons

When they have gained electrons