Asap, ! i also have another question that has yet to be answered (it's a chemistry question) that's worth the same amount of points as this one. explain how the existence of ions relates to the number of electrons present in atoms of an element?

I forgot this one, but I learned this in physics class. It had something to do with there being more or less electrons for how ever many photons there is in an atom.

Example: Hydrogen has 1 photon which usually means there is one electron, but when there is more electrons than photons, that is a negative ion. When there's less electrons than photons, that is a positive ion.

hope this helps

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf