One type of chemical process that can be either exothermic or endothermic is dissolving of salts in water. A salt is a compound made up of positively charged ions and negatively charged ions which are held together in a solid state because the positive and negative charges attract one another.
Carbon dioxide is a compound. Oxygen is an element. A compound is 2 or more elements chemically combined. An element is a pure substance. A mixture is combining two or more different compounds/elements.
Answer:
change of color
Explanation:
when a substance undergoes a change of color it is an indication that it was chemical
I think this is how to do it. but I'm sorry if it's not exactly right
Fuel cells work by passing hydrogen through the anode of a fuel cell and oxygen through the cathode. On the anode site, hydrogen molecules are split into electrons and protons. They have a high efficiency therefore these fuel cells are also considered to be very clean plus a fuel cells only by-products are electricity, excess heat, and water.
