Mr. Adkins
Unit 1
Properties of matter and changes of matter
Matter: anything that has mass and takes up
space
Any substance that has a definite composition
◦ Always made of the same stuff in exactly the same
proportions
Examples: H2O, NaCl, C12H22O11
All around us
Changes in chemicals
◦ Ex: things growing, food cooking, taking a photo (film)
We use reactions to produce chemicals
◦ Ex: plastics, acids
◦ What is the difference between ice, water, steam?
Solid
Liquid
Gas
Plasma
Definite shape
Definite volume
Nonfluidity
Definite melting point
High density
Incompressibility
Examples of Solids
• Wood
• Iron
• Paper
• Gold
2 types of solids
◦ Crystalline solid (crystal)
Arranged in an orderly, repeating pattern
◦ Amorphous solid (without form)
Arranged randomly – no pattern
The total 3-dimensional array of points that
describe the arrangement of particles in a
crystal is called a crystal lattice.
1 repeating piece
is a unit cell
No definite shape
Definite volume
Fluidity – able to flow
Relative high density
Relative incompressibility
Dissolving ability
Ability to diffuse
Tendency to evaporate and boil
Tendency to solidify
Examples:
Water
Apple Juice
Blood
◦ No fixed Volume
Expand to fill container
◦ No fixed Shape
◦ Atoms/molecules
Far apart!
Not very organized!
Particles have lots of energy.
◦ Particles can flow
Slide past one another
Example:
Oxygen
Helium
Nitrogen
Pressure (atm)
(Freezing
Points)
Liquid
1
Solid
(Boiling
Points)
.
Gas
(Triple
Point)
0
100
Temperature (oC)
Properties that can be measured or observed
without changing it’s identity
◦ Length, mass, color, odor, density, boiling point,
melting point
Matter can change
◦ Ice melts, water fogs a mirror, bike spokes
rust, red clothes fade, milk sours
2 types of changes
◦ Physical Change
◦ Chemical Change
A change in which the identity of a substance
does not change
◦ Change physical properties
Melting, freezing, dissolving, crushing,
tearing, folding, boiling
Also called a chemical reaction
Things turn into something NEW
2 parts of a chemical reaction
◦ Reactants – things that react
◦ Products – things that are produced
Example: Burning, Combusting, Tarnish,
Exploding, Molding, Rusting, Cooking
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Iron metal is melted
Iron combines with oxygen to form rust.
Wood burns in air.
A rock is broken into small pieces.
Milk turns sour.
You make scrambled eggs.
You step on a piece of chalk and it becomes
powdered.
You light a candle when the electricity goes out.
Steam from you hot shower condenses on a cold
mirror.
Combustion of gas in a car
Wood chopped into pieces
Boiling water
Baking cookies
Bending a silver spoon
Digesting food
Reactant + Reactant Product + Product
Propane + Oxygen Carbon Dioxide + Water
1.
2.
3.
4.
1 of 4 things must happen
A gas is produced (bubbles are gas)
Formation of a precipitate (solid)
Release of heat and light
Color change
All matter is made of atoms
◦ There are approximately 115 kinds of atoms
Matter is either a pure substance or a mixture
2 Types
Can it be separated?
◦ Yes, it is a compound
H2O, NaCl, C6H12O6, H2SO4
◦ No, it is an element
H, O, Na, Au, Pb
2 Types
Is it all the same?
◦ Yes, it is a homogeneous mixture
Tap water, air, apple juice, creamy peanut butter,
◦ No, it is a heterogeneous mixture
Salt/pepper, orange juice, choc chip cookie, chunky
peanut butter, chicken noodle soup
Calcium
Gasoline
Lucky Charms Cereal
Bronze
Table Salt
Copper
Oatmeal Raisin Cookies
Carbon monoxide
Pure oxygen
Oil and Vinegar Salad Dressing
Na2SO4
3 kinds of mixtures
1. Solution
Solute
Solvent
◦ Soluble – will dissolve
◦ Forms a homogeneous mixture
Very small particles
◦ 2 Parts of a solution
Solute – stuff that dissolves
Solvent – stuff that the solute dissolves in
Solution
Solute
Solvent
Example
Gas
Gas
Air
Gas
Liquid
Soda Water
Gas
Solid
-
Liquid
Gas
Humidity
Liquid
Liquid
Juice in water
Liquid
Solid
-
Solid
Gas
Sulfur in air
Solid
Liquid
Kool Aid
Solid
Solid
Alloy (Brass)
2. Suspensions
◦ Heterogeneous mixture that settles
◦ Large particles
◦ Muddy water, Italian salad dressing
(anything that must be shaken)
3. Colloids
◦ Intermediate sized particles
◦ Particles disperse
2 parts of a colloid
◦ Tyndall Effect
Seeing a beam of light
(separates colloid from solution)
Colloid
Phase
Gel
solid dispersed in liquid
Liquid emulsion
liquid dispersed in liquid
Foam
gas dispersed in liquid
Smoke
solid dispersed in gas
Fog
liquid dispersed in gas
Smog
solid & liquid dispersed in gas
Solutions
Colloids
Suspensions
Homogeneous
Very small
particles
Does not
separate
No light
scattering
Homogeneous
Intermediate
sized
Does not
separate
Tyndall effect
Heterogeneous
Large particles
Separates
No Tyndall
effect
Increasing the Rate of dissolving
◦ 1.
Increase the surface area of solute
◦ 2.
Agitating the solution (stirring)
◦ 3.
Heating the solvent
Electrolyte
◦ A solution that has ions in it and can conduct
electricity
Saturated solution
◦ Contains the maximum amount of solute
Unsaturated solution
◦ Contains less than the maximum amount of solute
Supersaturated solution
◦ Contains more than the maximum amount of solute
(Rock candy, crystals)
Unsaturated: Too Little
Saturated: Just Right
Super Saturated: Too Much!
1. Types of solvents and solutes
◦ Like dissolves like
Refers to polarity
Water is a polar molecule
Oil is a nonpolar molecule
If they are the same polarity, the compounds are
miscible (mixable) - salt in water, vinegar in water
If they are not soluble, they are immiscible (not
mixable) - oil in water, salt in oil
2. Pressure
◦ Under pressure a gas will enter and dissolve in a
liquid
fizz in a bottle of pop
◦ If pressure is released, the liquid can’t hold as
much gas
Effervescence
3. Temperature
◦ Warmer liquids hold less gas
Burp more from warm pop