7

nucleons

mass of proton

mass of neutron

The number of protons determines the

Atoms that have the same number of protons
but differ in the number of neutrons are

The closer an electron is to the nucleus, the greater is its

The total number of electrons in the orbital shells is
exactly equal to the number of

If an atom has an extra electron or has had an electron
removed, it is said to be

is not
electrically neutral but carries a charge equal in magnitude to the difference between the numbers of electrons
and protons.

is the removal or addition of an
orbital electron from an atom.

electron added to an inner shell after interuption

remaining electron

center seeking force
keeps an electron in orbit

flying out from the center
electrons maintin their distance from the nucleus while traveling in a circular or elliptical path

symbol of mass number

symbol of amu

Atomic nuclei that have the same atomic mass
number but different atomic numbers are

Atoms that have the same number of neutrons
but different numbers of protons

have the same atomic number and the
same atomic mass number.

Atoms of various elements may combine to form
structures called

is any quantity of one
type of molecule