Answer:

Explanation:
You must convert the mass of B₄H₁₀ to moles of B₄H₁₀, then to molecules of B₄H₁₀, and finally to atoms of H.
1. Moles of B₄H₁₀

2. Molecules of B₄H₁₀

3. Atoms of H

Answer:
Third Law of motion. (answer C)
Explanation:
This is an example of Newton's Third Law of motion which normally translates into Action/Reaction. That is : the expelled air exerts a force in the direction opposite to that of the motion of the air that goes out. It is the same as propulsion in a rocket.
Answer:
Should be either mendele or fermium
maybe lawrencium not sure but I think it’s lawrencium! Sorry if wrong heh
Explanation: <u><em>really trying to help! If it’s wrong super sorry!!!</em></u>
Explanation:
Significant figure is the measure of how accurately something can be measured. It carries meaning contributing to its measurement resolution. It is important to use proper number of significant figures to get a precise measurement. For example, if we use a meter stick then measurements like 0.874 meters, or 0.900 meters, are good because they indicate that we can measure to the nearest millimeter. Whereas a measurement like 0.8 does not tell that a meter stick can measure to the nearest millimeter.