1. Pure Substances and Mixtures

2. Pure Substances Cannot be separate by physical means Elements
Found on the Periodic Table
Ex) Li; Al; Fe; Cu; etc. There are lots of them…
Compounds
two or more elements (not mixed with anything else)
Ex) H2O; K3N; H2SO4; C12H22O11; etc. The list goes on and on

3. Mixtures Can be separate by physical means Homogenous mixture
Looks the same throughout
Ex) salt water or cough medicine
Heterogeneous mixture
Can tell a difference between the parts
Ex) sand in salt water or a precipitate in solution