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 substances are any materials (in any state-solid, liquid or gas) that have a definite chemical composition. Chemical substances can therefore be either a pure chemical element or a pure chemical compound. Chemical substances are any materials (in any state-solid, liquid or gas) that have a definite chemical composition. Chemical substances can therefore be. a pure chemical element. a pure chemical compound.