Here is the answer. I am not sure how to explain it! Sorry!
C. The lowest mass will be the element in period 1, group 1 (this element is hydrogen)
Many organisms need clean drinking water and we also need moisture in the air for us to stay hydrated
The chemical at the heart of the air bag reaction is called sodium azide, or NaN3. CRASHES trip sensors in cars that send an electric signal to an ignitor. The heat generated causes sodium azide to decompose into sodium metal and nitrogen gas, which inflates the car's air bags.