Parts of an Atom. What is an atom?. Atoms are the fundamental building blocks of all things Atoms are the most basic unit of matter Atoms contain three different types of subatomic particles. Atoms are made up of protons, neutrons, and electrons
Electrons exist in orbitals or energy levels
2 electrons fit in the first energy level
8 electrons fit in each subsequent energy level
2 in first level, 4 in second
The charge indicates the number of electrons that have been lost or gained.
Atoms of the same element with differing numbers of neutrons are called isotopes
The combinations of two or more elements in definite proportions form a chemical compound.
H20 = 2 parts hydrogen to 1 part oxygen
The physical and chemical properties of a compound are usually very different from those of the elements from which it is formed.
2 types: Ionic, Covalent
Ionic bonds are formed when one or more electrons are transferred from one atom to another