Asubstance is composed of only one kind of atom and can't be separated into simpler substances or converted into another substance by chemical processes. under which category would you classify this substance?

Does the energy in a solid increase or decrease when changing to a liquid?

Nuclear fusion is the source of energy for stars. besides hydrogen, which other element is most likely also common in stars?

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.