I believe the answer is A the 1st one
ANSWER:
Potential energy due to the position of an object above Earth's surface is called gravitational potential energy.
EXPLANATION:
Gravitational energy is the potential energy compared with gravitational force, as work is needed to further things against Earth’s gravity. The potential energy due to high positions is called gravitational potential energy, and is evidenced by water in an elevated storage or kept behind a dam. If an article falls from one point to different point inside a gravitational field, the force of gravitation will do actual work on the object, and the gravitational potential energy will decrease by the same amount.
Explanation:
A nuclear fission reaction is defined as the reaction in which a heavy nucleus splits into small nuclei along with release of energy.
The given reaction is 
Now, we balance the mass on both reactant and product side as follows.
235 + 1 =
236 = 234 + x
x = 236 -234
= 2
So, now we balance the charge on both reactant and product side as follows.
92 + 0 = 
92 = 96 - y
y = 4
Thus, we can conclude that there are 2 neutrons and 4 beta-particles are produced in the given reaction.
Therefore, reaction equation will be as follows.

<span>Percent yield is the measured recovery of a substance in grams divided by the theoretical amount of substance expected in grams (times 100 to convert to %). Undissolved Aluminum trihydroxide would add mass to the Aluminum sulphate one is making here. The measured mass would be inaccurately high, increasing the percent yield calculated.</span>
meaning:An acid is a chemical substance, usually a liquid, which contains hydrogen and can react with other substances to form salts. Some acids burn or dissolve other substances that they come into contact with.