yes substances Do react by mass
Answer: Heating the hydrated forms of cobalt chloride reverses the reactions above, returning cobalt chloride to the blue, water-free, or anhydrous, state. Water is "liberated" in these reactions, known as dehydration reactions.
Explanation:
Answer is: The total energy in the system remains the same as the decrease in chemical energy equals the increase in thermal and radiant energy.
The law of conservation of energy states that the total energy of an isolated system remains constant; energy can neither be created nor destroyed; it can only be transformed or transferred from one form (in this example chemical energy) to another (in this example thermal and radiant energy).
Radiant energy or light is the only kind of energy we can see with our eyes. Light have different wavelenght and different color.
Chemical energy - this type of energy is often found in things like batteries or food.
I would be inclined to go with A, C and D
In magnet I believe nickle is used most often
