1. Mixture
• Two or more substances that are not
chemically combined
• All mixtures can be physically separated
• Ways to separate mixtures
– Distillation-use boiling point
– Magnet-uses magnetism
– Centrifuge-use density
– Filtering-separates large particles from
smaller ones
2. • Ratio of mixtures are not fixed
• Substances keep their identities
• Mixtures can be solid, liquid or gas
• Examples of mixtures
– Chex mix
– Raisin bran
– Pizza
– Mixed nuts
– air
3. Solutions
• Mixture that appears to be a single
substance
• Material is evenly distributed by dissolving
• Material must be soluble (able to dissolve)
• Solute is what is dissolved
• Solvent what the solute is dissolved in
• Water is the universal solvent
4. • Materials that will not dissolve (insoluble)
forms a mixture that is not a solution
• Examples of solutions
– Sodas
– Gasoline
– Ice tea
– Salt water
– Kool aid
5. • In solutions the particles are so small they
never settle out (sink to bottom), can’t
scatter light nor can they be filtered
• Solubility is the ability of substances to
dissolve at a given temperature and
pressure
• How much of a solute a solvent can hold
is the concentration (grams of
solute/milliliter of solvent, g/mL)
6. • To increase solubility you can change
temperature, crush, stir, shake
• Homogenous solutions– meaning the
same
• Heterogenous solutions– meaning
different
7. Suspensions
• Suspensions are mixtures where the
particles are heavy enough to settle out
(sink to bottom) of the solution, scatter
light, can be filtered
• Examples of suspensions
– Snow globe
– Italian dressing
8. Colloids
• Colloids are mixtures where the particles
are evenly dispersed but are not heavy
enough to settle out, can scatter light,
can’t be filtered
• Examples of colloids
– Mayo
– Whip cream
– pudding
9. Elements
• elements are pure substance that can not
be separated into simpler substances by
physical or chemical means
• Pure substance is a substance with only
one type of particle called atoms
• All atoms of an element are identical
regardless of how much you have
10. • Elements can be identified by their
characteristic properties
• The properties, both chemical and
physical do not depend on the amount of
the element present
• Elements can have similar properties but
each element has some property that
makes it unique
11. • Elements are classified by categories
• Metals – shiny, good conductors
• Nonmetals – dull, poor conductors
• Metalloids –has properties of metals and
nonmetals depending on conditions
• Categories allow unknown elements to be
placed in the periodic table based on
similar properties
12. Compounds
• Pure substance composed of two or more
elements that are chemically combined
• Compounds are formed by elements
reacting or having a chemical change
• A particle of a compound is a molecule
• Elements do not form compounds
randomly
• All compounds are formed from only the
elements on the periodic table
13. • Compounds form in specific mass ratio
• Ex: mass of hydrogen to mass oxygen in
water is hydrogen 1 to oxygen 8 which can
be written as 1:8. For every molecule of
water, the ratio is the same, if the ratio is
different, then the compound can not be
water
14. • When elements form compounds, new
characteristics properties are created
• Compounds have properties that differ
from the elements that formed them
• Na (sodium) reactive alkali metal + Cl
(chlorine) poisonous gas → NaCl (table
salt)
15. • Some compounds can be broken down into their
elements by a chemical change
• Other compounds break down into simpler
compounds instead of elements
• The only way to separate a compound into
elements or other compounds is by a chemical
reaction which allows for a chemical change
• Two ways: is to apply energy or electric current
