Answer:
The differemt isotopes that differ in atomic mass
Explanation:
DNA and RNA is your answer
Answer: He could add a base to the pool to neutralize the acid.
Explanation:
Chlorine is used to disinfect the pools as it produces hypochlorous acid in water. This hypochlorous acid is unstable and gives hydrochloric acid and nascent oxygen which is used to disinfect.

The excess acid is neutralized by adding base which produces salt and water and thus decrease the acidity.

Adding more acid would increase the acidity further.
Answer:
Yes.
Explanation:
Hydrogen-filled balloons were widely used by the militaries during World War I (1914–1918). The main purpose of these hydrogen-filled balloons to detect movements of enemy troops and to provide direction to the artillery fire. Balloons were the targets of opposing aircraft because they knew the purpose of these balloons so they hit it whenever seen by the enemies so we can say that both sides used hydrogen-filled balloons as military observer to watch the enemy's movements.
I think it’s B energy of the reactants