Lets Review –
•The basic building blocks for all matter is an atom. • •An element is a substance consisting of a single type of atom. Molecules •A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound •Made up of two or more atoms •The atoms can be the same or different. Examples of molecules •O2 – oxygen •O3 - ozone molecule •H2O – water •CO2 - carbon dioxide •H2SO4 – sulfuric acid Molecules •Formed when two or more atoms bond together chemically •Elements can bond with the same atoms or different atoms. •These bonds form as a result of the sharing or exchange of valence electrons among atoms. Compound •A chemical substance formed when two or more different elements bond in a specific proportion. •The elements lose their individual chemical properties and the compound has new properties. •Chemical bonds are a result of the sharing or exchanging electrons among the atoms. •The smallest unbreakable unit of a compound is called a molecule. Chemical Formula •The recipe for a chemical substance •Tells the number of atoms of each element in a compound or molecule •Uses symbols for the elements present and subscripts (small numbers) to indicate the number of elements •Ex. H2O - water Chemical Equation •A shorthand that scientists use to describe a chemical reaction •The number in front of the element symbol (called a coefficient) indicates the number of molecules. •If no coefficient appears in front of a molecule, we interpret this as meaning one. |
Erik E. Mason
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