Temp exo: product- add>reactant | remove> product
endo : reactant- add>product | remove>reactant
Catalyst: low activation energy , inc reaction rate.
Chemical R: bonds are broken & formed.| valence electrons| small energy|same identity | Temp+pressure+catalyst affect reaction rate.
Nuclear: nuclei combine, split, emit radiation.| p+e+n | large energy | atoms convert | temp + press don't affect.
X rays and gamma are form of high energy electromagnetic radiation. X rays are emitted From materials that are in an excited state. Gamma rays are produced by radioactive sources.