Acation forms when an atom gains an electron. a cation forms when an atom gains an electron. a. true b. false

Which substances have the lowest melting points: ionic covalent, or metallic

Particles vibrate in a rigid structure and do not move relative to their neighbors.

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.