C. the number of protons and neutrons an element has in its nucleus
Answer:
See the answer below
Explanation:
<em>First, it should be understood that an endothermic reaction is one that absorbs energy in the form of heat from the surrounding.</em> The products of endothermic reactions usually have higher energy than their reactants. Hence, the ΔH° which is referred to as the enthalpy change is usually positive.
<u>Forgetting to cover the coffee-cup calorimeter means some of the heat energy absorbed by the reactants would be exchanged back to the surroundings - a loss.</u> It also means that the enthalpy change would be smaller compared to if the cup had been covered because some of the heat has been lost to the surrounding.
Chemical would be the correct answer
A triple bonded carbon is called an alkyne. (with a y, e for double bond, a for single bond)