Beginning of Essay
is the study of atoms. Atoms are the smallest forms of matter that can still be considered/recognized as elements. Atoms are what make up everything on our earth, from molecules to monkeys. Atoms are joined together to make molecules, which are in turn joined tog ....

Middle of Essay
.... wighing it. In the 20th century, most scientists used oxygen as the standard gas to compare other gases' weights. It is relativly easy to measure the weights of liquids and sloids, the same procedure for gas is followed, more or less. In the early 1960s, though, the international union of chemistry and physics agreed that there would be a new standard, carbon isotope (carbon-12). British physicist Ernest Rutherford found and proved that an atom's mass is concentrated in its its nucleus, which is the center of the atom. He also gave the idea that parts of an atom, called its electrons, orbit the nucleus. He said that the electrons were "negatively ....