What does a Gram Negative stain show? - Stains the background of bacteria - The dye does not stick to the specimen, instead settles around its boundaries, creating a silhouette
A chemical element is a pure substance which is composed of a single type of atom, characterized by its particular number of protons in the nuclei of its atoms, known as the atomic number and represented by the symbol Z. The mass number is the sum of the number of protons and neutrons in a nucleus.
Chemical compound, any substance composed of identical molecules consisting of atoms of two or more chemical elements. 1  All the matter in the universe is composed of the atoms of more than 100 different chemical elements, which are found both in pure form and combined in chemical compounds.