When a substance is boiled, what happens to the mass?

a. the mass increases as it changes from a liquid to a gas
b. the mass stays constant from a liquid to a solid
c. there is no mass once the substance becomes a gas
d. the mass decreases as it changes from a liquid to a gas

When a scientific theory has been tested and proved by the scientific community, it becomes a law

Phosgene (carbonyl chloride), cocl2, is an extremely toxic gas that is used in manufacturing certain dyes and plastics. phosgene can be produced by reacting carbon monoxide and chlorine gas at high temperatures: co(g) cl2(g)⇌cocl2(g) carbon monoxide and chlorine gas are allowed to react in a sealed vessel at 477 ∘c . at equilibrium, the concentrations were measured and the following results obtained: gas partial pressure (atm) co 0.830 cl2 1.30 cocl2 0.220 what is the equilibrium constant, kp, of this reaction

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.