1. antoine lavoisier, a french scientist, established which principle? a. mercury and oxygen are nonreactive. b. an open system is required to observe changes in mass. c. the total mass of the products of a reaction is always slightly more than the total mass of the reactants. d. the total mass of the products of a reaction is equal to the total mass of the reactants.

The correct option is d.

Explanation: Antoine Lavoisier is a french scientist who discovered the role of oxygen in the process of combustion and respiration.

He was famous for the law of conservation of mass.

This law states that the total mass the reactant will equal to the total mass of the products in a chemical reaction.

For example: Combustion of methane

Mass of the reactants =

Mass of the products =

Hence, every chemical reaction will follow law of conservation of mass.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.