20km every 1 hr is what 20km/hr means.
so 3hrs is 20km*3=60km.
Atoms are basically tiny structures that make up everything. And a compound is something used in a scientific expirement. I don't get the question. You used improper grammar
<span>Its the impact theory.
It suggests that the moon resulted from the collision of two protoplanets, or embryonic worlds. One of those was the just-forming Earth, and the other was a Mars-size object called Theia. The moon then coalesced from the debris, thus giving it its irregular shape.</span>
Mass is the amount of matter it has, while weight <span>is a measurement of the force placed on an object by gravity. An example of how they are different is that mass is always constant while weight varies depending on the location.</span>
