Which two properties are used to define matter?
a. has mass and conducts heat
b. has buoyancy and volume
c. has mass and takes up space
d. conducts energy and has characteristic properties

The two properties which are used to define matter are that it has mass and it takes up space. The other properties do not necessarily apply to each matter. Such some matter can be a conductor of heat (such as metal) and some not (such as non metals). Likewise, some matter can be buoyant and float on liquid of density more than it but others would not on the liquids of density less than it. In-fact not all the matters are conductors of energy (such as heat, sound, electricity) or at-least a very poor conductor of energy and tend to find application as insulating agents (non conductors). So the only thing which is necessarily true is that the matter would definitely have mass in even their minutest form as atom and would take up some space.