A reaction is said to be spontaneous when it can proceed in either the forward or reverse direction. True. A reaction can have a negative Gibbs Free Energy in both directions. True. This is the definition of spontaneity. False. A reaction that can proceed in either forward or reverse directions is in equilibrium. False. A reaction can only have a negative Gibbs Free Energy in one direction.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.