Element – a pure substance that cannot be broken down
into any other substances by chemical or physical means.
All items on the periodic table are elements.
All elements are represented by a symbol.
Examples: carbon C
Compound – a new substance created by a chemical
reaction when 2 or more elements combine.
Compounds can only be broken down by another
Example: sodium (Na) + chlorine (Cl) = salt
Chemical Equation – a short, easy way to show a chemical
reaction, using symbols instead of words.
Examples: Na + Cl NaCl
H2 + O H2O
C + O2 CO2
Mixture – two or more substances that are mixed together
but are not chemically combined.
Examples: raisins & oatmeal
sugar & cereal
salt & water