Answer: C. The sign of the enthalpy of the reaction reverses.
Explanation: Enthalpy of a reaction is the net heat absorbed or released during a chemical reaction.It is represented by 
. It is negative for exothermic reactions in which heat is released and is positive for endothermic reactions in which heat is absorbed.
When a chemical reaction is reversed the heat of the reaction changes its sign.
The decomposition of calcium carbonate is an endothermic reaction as heat is required to break the bonds and thus energy is absorbed.
When the reaction is reversed, the reaction becomes exothermic as now bonds are getting formed and energy is released.
On the line above the tree line
Oil Coal and Natural Gas are the fossil fuels the USA has the most reserves of. Given that only one of them is on the answers Coal is the correct answer.
Answer:
A) all the genes that occur in the population.
Explanation:
The gene pool is defined as the set of all genes in population. The larger the genetic pool in population is, the grater genetic diversity is so the population can survive intense process of selection. On the other hand, low genetic diversity can cause reduced biological fitness and the chance of extinction is increased.
