Substance Substance is a type of material with a fixed
composition A substance can be either an element or a compound
Examples: Water, salt, helium
Slide 3
Substance All substances are built from atoms
Slide 4
Substance Element substance with atoms that are all alike
Examples are Zinc, copper, carbon Elements are found on the
periodic table
Slide 5
Substance Compounds substance formed by two or more elements in
a fixed portion Water is a compound always made of one oxygen and
two hydrogens
Slide 6
Mixtures Mixture is a material made up of two or more
substances that can be easily separated by physical means Mixtures
do not always have to have same proportions.
Slide 7
Mixtures Heterogeneous Mixtures are mixtures in which different
materials can be distinguished easily Does not always mean it is
easy to see just easy to separate by physical means
Slide 8
Mixtures Homogeneous Mixtures mixtures that contain two or more
gaseous, liquid or solid substances blended evenly throughout the
entire mixture. Solutions are another name for homogeneous
mixtures
Slide 9
Mixtures Colloid a type of mixture with particles that are
larger then those in solutions but not heavy enough to settle out.
Colloids can be determined because their particles are large enough
to scatter light, this is called the Tyndall effect.
Slide 10
Mixtures Suspension heterogeneous mixture containing a liquid
in which visible particles settle. Example pond water, some mud
particles settle out and the water clears
Slide 11
Physical Properties Physical properties any characteristic of a
material that you can observe without changing the identity of the
substances that make up the material
Slide 12
Physical Properties Appearance what does it look like Behavior
how does it act in different situations Is it rough or smooth,
bounce or roll
Slide 13
Physical Change Physical change is a change in size, shape, or
state of matter. The substance does not change just the appearance
and behavior Example: freeze, boil, evaporate or condense
Slide 14
Physical Change Distillation is the process for separating
substances in a mixture by evaporating a liquid and recondensing
its vapor Can be used to get other materials out of water
Slide 15
Chemical Properties Chemical property is a characteristic of a
substance that indicates whether it can undergo a certain chemical
change Burning something causes a chemical change Rusting is a
chemical change
Slide 16
Chemical Change A chemical change is when a substance undergoes
a change in which a new material is formed. When Iron oxidizes it
forms rust and changes color Substances can be separated using
chemical changes A chemical reaction can turn tarnished materials
back into what they were originally
Slide 17
Law of Conservation of Mass The law of conservation of mass
says that the mass of all substances that are present before a
chemical change equals the mass of all substances that remain after
the change.
Slide 18
Solids, Liquids and gases Draw picture of the particles of
solids, liquids and gases Label the movement of particles of each
Label how it is shaped
Slide 19
Kinetic Theory Kinetic Theory is an explanation of how
particles in matter behave Three assumptions 1. All matter is
composed of small particles 2. These particles are in constant,
random motion 3. These particles are colliding with each other and
the walls of their containers
Slide 20
Heating and Cooling Melting point the point at which a solid
begins to liquefy Heat of fusion the amount of energy required to
change a substance from the solid phase to the liquid phase at its
melting point
Slide 21
Heating and Cooling Boiling point is the temperature at which
the pressure of the vapor in the liquid is equal to the external
pressure acting on the surface of the liquid Heat of vaporization
is the amount of energy required for the liquid at its boiling
point to become a gas.
Slide 22
Heating and Cooling Draw heating and cooling curves and label
heat of fusion and heat of vaporization.
Slide 23
Diffusion Diffusion is the spreading of particles throughout a
given volume until they are uniformly distributed. The more dense a
gas is the longer its diffusion rate
Slide 24
Plasma Plasma is matter consisting of positively and negatively
charged particles. The number of positively charged particles
equals the number of negatively charge particles so the overall
charge is neutral. Stars, sun, lightning bolts, neon and
fluorescent bulbs are all things consisting of plasma Scientist
estimate that much of the matter in the universe is plasma.
Slide 25
Thermal Expansion Thermal expansion is an increase in the size
of a substance when the temperature is increased. Solid thermal
expansion bridge Liquid thermal expansion liquid in a thermometer
Gas thermal expansion hot air balloons
Slide 26
Water and thermal expansion Why does water not follow the rules
for thermal expansion?
Slide 27
Unusual Substances Amorphous Solids Plastics and glass They
melt over a range of temperatures not a specific melting point
Liquid Crystals These are used to make liquid crystal displays
(LCD)
Slide 28
Properties of Fluids Buoyancy is the ability of a fluid to
exert an upward force on an object immersed in it If the weight of
the object is equal to the buoyant force the object will
float.
Slide 29
Archimedes Principle When an object is placed in water, the
object will push the water out of the way as it begins to sink. It
will stop when the weight of the water displaced equals the objects
weight
Slide 30
Density If an object is more dense then the fluid it is in it
will sink If an object is less dense then the fluid it is in it
will float
Slide 31
Pascals Principle Pascals Principle says that pressure applied
to a fluid is transmitted throughout the fluid Example toothpaste
tube
Slide 32
Bernoullis Principle Bernoullis Principle says that as the
velocity of a fluid increases, the pressure exerted by the fluid
decreases Paper example
Slide 33
Viscosity the resistance to flow by a fluid Syrup has a high
viscosity, flows slowly Water has a low viscosity, flows
quickly
Slide 34
Behavior of Gases Pressure is force exerted per unit area
Pressure is measured in a unit called pascal (Pa). Earths
atmosphere has pressure exerting all around us.