The ER comes in two different morphological forms: smooth ER and rough ER
The combined mass of rock 1 and 2 = 19.28 + 25.3
= 44.58
Difference between rock 3 and combined rocks
= 46.3 - 44.58
= 1.72 grams
therefore, the third rock was 1.72 grams greater than the combined mass of the other two rocks.
Archaea means ancient, bacteria are, well, minuscule organisms that live everywhere, and eukarya are organisms with cells that have a nucleus as well as membrane-bound organelles... my best guess if it is planets you mean, then the answer would be archaea, if it is plants, like flowers or such, then it is eukarya.
I hope this helps!
