Chemistry

Chemistry is the science concerned with the composition, structure, and properties of matter.

Atoms are the basic units in chemicals.

Atoms are made of subatomic particles.

• protons (+)• neutrons (0)• electrons (-)

An element is a pure substance made up of only one kind of atom.

All matter is made up of elements.

Reading the Periodic Table

Molecules

• atoms combine to form molecules, which can be pure elements or combinations of two or more elements.

• molecules are held together by chemical bonds.

NaCl

NaCl in Solution

Covalent Bonds

• formed when atoms share electrons

• sharing can be unequal

Chemical Reactions

• reactants• products

example:

CO2 + H2O C6H12O6 + O2

Acids and Bases