Can a tank of oxygen gas ever be half empty?

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?

Which law represents the thermodynamic statement of the conservation of energy of a system? a. the fourth law b. the first law c. the second law d. the third law

Acrow drops a 0.11kg clam onto a rocky beach from a height of 9.8m. what is the kinetic energy of the clam when it is 5.0m above the ground? what is its speed at that point?