Answer:
Mg
Explanation:
Magnesium has a valency of +2
Answer:
C
Explanation:
A negative deltaH means that the reaction has to give up heat in order to happen. You have to treat deltaH as a reactant. So the question is do you need to add heat to the reactants to make the products. If you do, deltaH is plus.
Heat is required to make a solid go to a gas. deltaH is plus. A is not the answer.
A lot of heat is required for B (something like 400 Kj / mole. Like A, deltaH is plus and B is not the answer.
C: The liquid has to give up heat in order for the this reaction to take place. C is the answer.
D requires heat. It is not the answer.
The correct answer is letter C. Rock Cycle. Living organisms involved in carbon cycle, oxygen cycle, and in nitrogen cycle. These are involved in the air that living organisms are taking in and out.
Answer:
When white glue is in the bottle, there's not enough air inside the bottle to cause the water to evaporate to make the glue sticky. Basically, the bottle holds the glue from the air and keeps the glue from going everywhere.
Answer:
One change of state happens when you add energy to the substance. This change of state is called melting. By adding energy to the molecules in a solid the molecules begin to move quicker and can break away from the other molecules. ... The temperature at which a substance goes from a solid to a liquid is it melting point.
