lnm

I am very thankful for every reply but I am still sort of confused. What, exactly, is radioactive decay? What is it that happens to an atom? Does it loose an electron/proton/neutron and is now a different element/isotope? Does the speed of any particle in it slow down and this is what a lose of energy means? Does a particle in it evaporate and ultimately I would end up with no atom at all? I am more interested in what is actually happening than in when it will happen or what the probability of it occurring is.

I know that half life is the time period for half the radioactive nuclei to decay. That if the half life of carbon 13 is 1000years... in a thousand years you'll have half the amount of carbon 13 as you did when you started. These are the sorts of explanations I can find but I would like to know what is actually happening. If I have one carbon 13 atom, do I end up with half the atom? Does it eventually disappear? What exactly is "radioactive decay"?

Has any life been found in space? Anything at all, viruses included.

Is it correct to say that one does not see an object but the light which bounces (or that it emits) of it?