A. element
and B. compound because they are both considered pure substances
I believe the correct answer is D
<span>Only one parent and the same chromosome
number as the parent.
</span>
The fire decreases since fire needs oxygen in order to burn
1. Ur graph should have 2 vertical lines || , of equal height at mass 13 and 15.
2. One, because you have the mass, which in this case is 13 and the other 15, which has the same height. So it must be the isotope. By definition, an isotope has the same number of protons, but different number of neutrons.
3. to solve for fractional abundance, Let x = fraction of element: "I"-13
then fraction of "I"-15 must be 1-x
so you have: 13x + (15<span>)(1-x) = 13
solve for x.</span>