Atoms

nucleons

protons

Proton number

Atomic number

Element

Periodic Table

92 Naturally-occurring

Largest naturally occurring is Uranium

Mass number 238

Atomic number 92

26 artificial

radioactive

created in nuclear reactors

Heaviest is ununoctium

Mass number 294

Atomic number 118

positive charge

Relative mass = 1

neutrons

Relative mass = 1

Minute volume within atom (1/15,000)

electrons

Negatively charge

Negligible mass

Charge clouds

Same proton number; varying numbers of neutrons

Element with largest number f isotopes is tin, with 10

Many are radioactive

Unstable, decay

3 isotopes

protium

1 proton, 1 electron

deuterium

1 proton, 1 electron, 1 neutron

tritium

1 proton, 1 electron, 2 neutrons

Radioactive