PLS HELP given a 5g example of k-40 calculate the amount of parents material that remains after 5.2x10^9 years

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 is the relation between concentration of reactants and the rate of chemical reaction?

Name the element in group 17, period 2. (periodic table)