Which of the following gases was most likely present in earth’s earliest atmosphere?
a. nitrogen
b. hydrogen
c. argon
d. oxygen

Aballoon inflated with three breaths of air has a volume of 1.7 l. at the same temperature and pressure, what is the volume of the balloon if five more same-sized breaths are added to the balloon? a balloon inflated with three breaths of air has a volume of 1.7 l. at the same temperature and pressure, what is the volume of the balloon if five more same-sized breaths are added to the balloon?

What semimetal can form four single covalent bonds.

Which answer lists the fundamental forces in order from strongest to weakest