I think it's D, because theoretical yield is like, the yield you'd get if 100% of the reactants formed to make product. Well that's how I think of it, but it has something to do with limiting reagents and stuff. Sorry this isn't a really detailed explanation.
Remark
The given thing on the right is a positron. The mass for these subatomic particles is considered to be 0. It's atomic number is 1 which means it is a blood relative of a proton.
So essentially what happens is that X is one space to the left on the periodic table. But let's solve this a little bit more formally.
Solution

y stays the same at 147. It is z that changes.
65 = z + 1 Subtract 1 from both sides.
64 = z
So the chemical with 64 as its position on the periodic table is
Gadolinium and the answer is C
<span>plasmas that reach a temperature equal to their surroundings
----------------------=0uyjgyhjngytfgbhtfgbdc b gdf gb </span>
Answer:
ya, it's gravity. What is the problem??
Explanation:
The name is 2-Chloro Propane
Because the chlorine is linked to the second carbon atom when it is spread out