Matter- has
mass and
takes up space
Substance composition
definite
Element - one
kind of atom
Compound two or more
kinds of atoms
Mixture composition
variable
Homogenous evenly mixed;
a solution
Heterogenous
- unevenly
mixed
Elements: The Purest Substance
 Cannot be separated into simpler substances by
physical or chemical means.
 Pure substance is a substance in which there is only
type of particle.
 Each element contains only 1 type of particle (atom).
Properties of Elements
 Do physical and chemical properties of elements
depend upon the amount of the element
 Answer: No
 What are some physical properties of elements?
 Boiling point, melting point, density, color, hardness,
texture, etc.
 What are some chemical properties of elements?
 Flammability, reactivity with acid and bases,
oxidation, etc.
Other Ways to Classify Elements
 3 major categories: metals, metalloids, and
nonmetals.
 Metals are shiny, malleable, ductile, and conduct
heat and electric current.
 Nonmetals are dull, brittle, and do not conduct
heat or electric current.
 Metalloids have properties of both metals and
nonmetals.
 Also called semiconductors
 How do you think metalloids look and behave?
Compounds: Made of Elements
 2 or more elements that are chemically combined.
 Elements combine by reacting or undergoing a
chemical change.
 A particle of a compound is a molecule.
 Examples include table salt, water, vinegar, carbon
dioxide, and baking soda
 Elements join in a specific ratio according to their
masses to form a compound.
 Every substance of water has the same ratio 1:8 of
hydrogen to oxygen.
Questioning the Compounds
 Does a compound have the same properties as its
elements?
 No
 How do you think a compound can be broken down?
 Chemical change
Mixing it Up with Mixtures
 Combination of 2 or more substances that are NOT
chemically combined. Ex: pizza
 Does not have to combine in specific ratios.
 No chemical change happens when a mixture is made.
 So each substance in a mixture has the same chemical
makeup it had before the mixture formed.
 Mixtures can be separated by a variety of physical
means. What are some ways you can think of?
Solutions
 Mixture that appears to be a single substance
(homogenous). Composed of particles of two or more
substances that are distributed evenly among each
other.
 The particles in solutions are so small that they never
settle out and cannot be removed by filtering.
 Example: sugar and water
Suspensions
 Mixture in which particles of a material are dispersed
throughout a liquid or gas but are large enough that
they settle out (heterogeneous).
 Particles are large enough to scatter or block light.
 Particles can be separated by passing it through a filter.
 Example: snow globe, pond water
Colloids
 Mixture in which the particles are dispersed
throughout ,but are not heavy enough to settle out.
Particles are relatively small and fairly well mixed.
 Cannot be separated by filtration because the particles
are small enough to pass through a filter.
 Examples: milk, mayonnaise, stick deodorant.