a is the answer because all of the other answers are wrtong
Answer:
A. Coefficients
Explanation:
that's the number in front of the molecules
The question ask for the percentage of the abundance of galium-69 where there is two isotopes of galium: the 69Ga and the 71Ga. The average atomic mass of gallium is 69.723 amu. So the formula would be <span>69.723amu=(%x)∗(68.926amu)+(1−%x)∗(70.025amu) and the answer to this is 1.58%</span>
B is true because plants can only use nitrogen in the form of nitrates, no other living thing needs nitrogen therefore the percentage of nitrogen in the atmosphere is 79%