Which materials undergo radioactive decay? check all that apply. atoms that are unstable elements that have a half-life atoms that release energy and particles elements that have turned into a new element elements that have a consistent number of particles

Atoms that are unstable undergo radioactive decay,

Elements with half life(that's how we know that it decayed),

Atoms that release energy and particles(like alpha beta and gamma particles) and,

Elements that have turned into a new element (as in radioactive decay no. of protons can decrease)

And to be precise the elements that have neutron to proton ratio of more than 1 undergo radioactive decay, since the nuclear attraction gets all weird after that.

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.