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.
Letâs break this down: A chemical is any substance that can be defined by its atomic or molecular composition. That covers a lot of ground! Any element is a chemical, an element being any substance that can be defined by a single atom. Thus hydrogen (H) and oxygen (O) are chemicals. Any compound is also a chemical, a compound being any substance defined by two or more bonded atoms. Thus water (H2O), consisting of bonded hydrogen and oxygen, is a chemical.