The reaction is exothermic, the energy in the bonds has been released to the surroundings (causing the potential energy to go down). The increase in energy in the surrounding heats them up hence exothermic.
Answer:
NaCl
Explanation:
because He which is helium gas its an element alone,
Cl which is chlorine is a single element,
B which is Boron and its a single element,
but NaCl which is simply called table sugar is the combination between Na, sodium and Cl, chlorine , so its called a compound not an element.
Answer:
c
Explanation:
there are billions of cells in living things. We are made out of millions of cells
An example is the cell theory