Unit 3 Vocabulary

element
proton
neutron
electron
quark
nucleus
antimatter
positron
gamma ray
atomic number
atomic mass
isotope
ion
alpha decay
beta decay
positron emission 
half life
fission
fusion
critical mass
subcritical mass
supercritical mass
valence electron
ionization energy
metals
non-metals
halogens
alkali metals
alkaline earth metals
transition elements
inner transition elements
noble gases