Elements and Compounds

• What is an element?

  A substance made up of one type of atom
• What is a compound?

  A compound is a substance composed of two or more elements chemically bonded together.
• What is a mixture?

  A mixture is a substance made of two or more elements not chemically bonded together
• When two elements join and one is a halogen (like oxygen or sulfur) the name ends with "-ide".

  Magnesium + oxygen = magnesium oxide

  Sodium + chlorine= sodium chloride
• When three or more elements join and one is oxygen the name ends with "-ide".

  Calcium + carbon + oxygen = calcium carbonate

  Zinc + nitrogen + oxygen= zinc nitrate
• A compound where 2 elements elements are hydrogen and oxygen, it's name ends with a hydroxide.

  Potassium + oxygen + hydrogen= potassium hydroxide
• The number of protons in an atom always equals the number of electrons.

  This means atoms have no overall charge - they are neutral.
• Compounds can only be separated by chemical reactions, physical processes cannot separate them.