Assistance with basic physics multiple choice questions?

>> - Marks what I believe to be the correct response.

I just want to make sure my review questions are correct before studying for my exam. Will pick best answer. Thanks.

1. If an oxygen atom is 16 times more massive than an hydrogen atom, how much more massive is the "amount" of oxygen separated from any amount of water than the "amount" of hydrogen?

a. Amounts of oxygen and hydrogen are equally massive

>>b. The amount of oxygen is twice as massive as the amount of hydrogen

c. The amount of oxygen is 8 times as massive as the amount of hydrogen

d. The amount of oxygen is 16 times as massive as the amount of oxygen

2. If we heated water to over 20000C it would become a

a. Solid

b. Gas

c. Liquid

>>d. Plasma

3. Liquid pressure is

a. Equal to the liquid's volume

b. Constant at all depths

>>c. Found by multiplying the liquid's weight density by depth

d. Both equal to the liquid's volume AND constant at all depths

4. In the case of the vacuum tube and movable stopper, what force moves the stopper?

a. The force of the vacuum

>>b. Atmospheric pressure

c. Gravity

d. Magnetic forces