The physical properties used by scientists to describe all matter, sight, smell, taste, color, texture, mass, weight, volume, and density.
Niels Bohr is the first person to describe a chemical reaction as the combination of atoms.
Gypsum has the same hardness as a fingernail
B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.