NS- Definitons Flashcards
Atoms
The smallest building block of all matter. It cannot be broken down further. It contains protons, electron and neutrons.
Element
A material that consists of atoms of only one kind.
Compound
A material that consists of two or more different element that have been chemically bonded. They can only be broken down by chemical means.
Molecule
A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound.
Diatomic Molecule
Molecules that are composed of only two atoms of the same kind. They are gases. H, N, O, Br, Fl, Cl and I.
Mixture
Two or more substances which have been combined such that each substance retains its own chemical identity. They can be separated by physical means.
Pure Substance
Substances that are made of only one type of molecule.
Impure Substance
A mixture of two or more kinds of molecules and has no definite composition and properties.