Element, Compounds, Mixtures and Isotopes

• Isotopes - an element with the same number of protons but different number of neutrons
• Molecule - two or more atoms held together by chemical bonds
• Compound - two or more different elements chemically bonded together
• Mixture - two or more elements or compounds not chemically bonded together
• Relative atomic mass - the average mass value which takes the mass and abundance of isotopes of an element into account.