In the chemical laboratory, why do scientists use a mortar and pestle? A. To increase surface area of a solute
B. To decrease surface area of a solute
C. To increase temperature of a solute
D. To decrease temperature of a solute

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

Complete the following reactions using word and balanced equations including states. dilute phosphoric acid is added with a calcium hydroxide solution.

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)