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.
n. 1. (Chemistry) any substance used in or resulting from a reaction involving changes to atoms or molecules, especially one derived artificially for practical use. adj. 2. (Chemistry) of or used in chemistry: chemical balance. 3. (Chemistry) of, made from, or using chemicals: chemical fertilizer.(ËkÉm Éª kÉl). n. adj.. a substance produced by or used in chemistry. 2. chemicals, Slang. narcotic or mind-altering drugs or substances. 3. of, used in, produced by, or concerned with chemistry or chemicals: a chemical formula. 4. used in chemical warfare: chemical weapons.