Science its comparing and contrasting metals and non metals and such have a lot of work to do for other

Metals are usually shiny, good conductors of heat and electricity, high melting point, high density, malleable, etc. non metals are poor conductors. Low melting point, dull/not shiny, brittle solids

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.