What is meant by the dual waveparticle nature of light

Which statement is a reason to support population regulation? a) it is unethical for us to control birth control rates b) humans have the freedom to produce as many children as desired c) the gap between the rich and poor has been narrowing since 1960 d) billions more people on the earth will intensify many environmental and social problems

What are transitions between a liquid and a solid called? identify which way they are transitioning

What is the molar mass of a gas that has density of 2.054 g/l