Answer: C
Explanation: Earth's atmosphere isn't very dense because it is made of air, which floats. Human beings are denser then air since they are solid, but not as dense as Earth's crust, which is rocky and the densest out of the three.
The answer is true. <span>A covalent bond is formed when atoms share electrons. </span>
Answer:
No.
Explanation:
Some organelles are found only in some cell types.
