Well none since molecules are a group of two or more atoms electrically bonded with one another. However, there are gases that does not naturally bond due to their stability and can be found in nature as pure elements. But these are not considered as molecules.
(By the way, these gases are the noble gases that can be found on the last column of the periodic table)
Answer:
I didn't do the observation so I can't help sorry
Answer:
<u>d. a row of elements</u>
Explanation:
Elements that are in the same group, have same number of electrons and make up a column in a periodic table.

Answer:
A. non renewable energy sources cannot be used over again and renewable energy sources can be used again