2. Mixtures
• A mixture is a combination of two
or more substances that are not
chemically combined.
• No chemical changes
• Sometimes you can see the
components, sometimes you
cannot
• Not mixed in a definite ratio
• Separate through physical methods
• Distillation- uses boiling points
• Magnets- use magnetism
• Centrifuge- uses density
• Filtering- separates according to size
• Examples:
4. Solutions
• A mixture that appears to be a
single substance
• Process by which they spread is
dissolving
• Solute- the substance being
dissolved
• Solvent- the substance doing the
dissolving (water is the universal
solvent)
• Particles never settle, cannot be
filtered; do not scatter light
Examples of Different States in Solutions
Gas in gas Dry air (oxygen in nitrogen)
Gas in liquid Soda (carbon dioxide in water)
Liquid in liquid Antifreeze (alcohol in water)
Solid in liquid Salt water (salt in water)
Solid in solid Brass (zinc in copper)
5. Concentration of Solutions
• Concentration- the measure of the amount of solute dissolved in a
solvent
• Can be expressed in grams of solute per milliliter of solvent (g/mL)
• Remember…solubility is the ability of a substance to dissolve
• Mixing, heating and crushing can help dissolve more quickly
6. Suspensions
• Suspension- is a mixture in
which particles of a material are
dispersed throughout, but are
large enough to settle out.
• Suspensions CAN be separated
by filtration
• Scatter light
7. Colloids
• A colloid is a mixture in which
the particles are dispersed
throughout and not heavy
enough to settle out
• Particles are small and fairly well
mixed; scatter light
• Cannot be separated by filtration
• Examples:
8. Elements
• Element- a pure substance that
cannot be separated into simpler
substances by chemical or
physical means
• Pure substance- is a substance in
which there is only one type of
particle
• Particles are atoms
• Each element has unique
properties- not dependent on
how much of an element you
have
• Remember…characteristic
properties? Physical and
chemical properties?
• Elements do share some
properties
• Grouped on the periodic table
by properties
9. Categories of Elements
Metals Nonmetals Metalloids
• shiny
• Good conductors of
heat and electricity
• Malleable
• Ductile
• dull
• Poor conductors of heat
and electricity
• Solids tend to be brittle
and not malleable
• Have properties of both
metals and nonmetals
• Semi-conductors
10. Compounds
• Compound- a pure substance composed of two or more elements
that are chemically combined
• Combine by reacting, undergoing chemical change
• Particles are called molecules, which are formed when atoms of two
or more elements combine
• Compounds are DIFFERENT from the elements that make it
• Elements join in specific mass ratios
• Ex: H2O = 1:8
11. Familiar Compounds
Compound Elements combined
Table salt Sodium and chlorine
Water Hydrogen and oxygen
Vinegar Hydrogen, carbon, oxygen
Carbon dioxide Carbon, oxygen
Baking soda Sodium, hydrogen, carbon, oxygen
12. Properties of Compounds
• Each compound has its own physical properties
• Can be identified by chemical properties
• A compound’s properties differ from the elements that formed it
13. Breaking down Compounds
• Broken down through chemical changes
• Sometimes have to be broken into simpler compounds, then
elements
• Two ways to break down: apply heat or electric current
