2 The relative atomic mass of an element is 21.5. The two isotopes of the elementare ,20"10X occurring
25% in nature and 10X occurring 75% in nature.
Calculate x.​

Energy is released during which phase changes? check all that apply. boiling condensing depositing freezing melting subliming

How does carbon monoxide pose the greatest threat to humans? a. it can be produced by wood fires. b. it can be produced by home furnaces. c. it is produced by acid rain. d. it is produced by modern automobiles.

What 3 categories are elements divided