Your answer is D. Because the Earth rotating on it's axis causes Day and Night
Chemical energy: When animals eat plant, they get the chemical energy in the plants stored as sugar.Mechanical energy: Carbon dioxide rising through the air gains mechanical energy (as well as gravitational potential energy).Thermal energy: The heating of fossil fuels releases the energy stored inside.Electrical energy: Burning fossil fuels creates electrical energy for us to use.
A carbon atom has 4 valence electrons