Energy & Matter
2.1, 1.1, 1.2, 1.3
1. Energy (2.1)
A. Energy: The capacity to do work or produce
heat.
1. 7 types of energy:
• mechanical
• thermal (heat)
• radiant (light)
• sound
• electrical
• chemical
• nuclear
2. Kinetic Energy: Energy of motion.
Ex. thermal,
mechanical
3. Potential Energy: stored energy;
determined by position.
Ex. Electrical PE, chemical PE
Potential and Kinetic Energy
4. Energy can be transferred from a system to its
surroundings.
Ex. Photosynthesis is light → chemical
Energy Transformations:
5. Energy absorbing changes are called
endothermic. If energy is released the change is
called exothermic.
B. Measuring Energy:
1. Common Unit: calorie The amount of heat
needed to raise 1 g of water 1 oC. (One
calorie = 1g°C)
2. SI Unit for energy: Joule (J)
C. Law of Conservation of Energy:
Energy is neither created nor destroyed, it just
changes form.
Temperature (2.1):
1. Energy can be transferred in the form of
heat.
2. Temperature is a measurement of heat or
kinetic energy. (how fast the average
particle is moving!)
Heat vs. Temperature Animation
Kinetic Energy (Temperature) and Melting
3. Common Temperatures
Fahrenheit (F)
Celsius (°C)
Kelvin (K)
Background Information
Popular
(1686-1736)
scientists
(1701-1744)
SI Unit
Absolute scale
(1824-1907)
Boiling Point of Water
212
100
373
Body Temperature
98.6
37
310
Room Temperature
70
20
293
Freezing Point of Water
32
0
273
Absolute Zero
-459.67
-273
0
98.6°F
Room Temp 70°F → Room Temp 20°C →
← Room Temp 293 K
4. Kelvin:
°C = K
K = °C + 273
°C = K - 273
5. The zero point on the Kelvin scale is called
absolute zero (-273°C)
6. All motion of particles stops! Therefore the
kinetic energy is zero.
2. Matter is anything that has
mass and takes up space.
1. Volume: Amount of space an object takes up.
2. Mass: Quantity of matter in a substance.
Constant everywhere. Ex) the moon
3. Weight: Force produced by gravity acting on a
mass. This is different in different locations.
Mass Vs. Weight
Mass does not depend on gravity.
The mass of an object remains the
same in all locations.
Weight and Mass Demo
Weight depends on gravity.
Weight equals Mass x gravity. The
weight of an object changes with
location.
B. Properties of Matter (1.2):
1. Physical: density, color, melting point, viscosity,
surface tension, specific heat
2. Chemical: flammability, reactivity with other
chemicals or air (O2)
C. States of Matter (1.1):
State
Shape
Volume
Movement
Structure
Solid
definite
definite
vibrational - slow
highly organized - crystal
Liquid
indefinite
definite
translational - medium
medium - fluid
translational - fast
low - random
Gas
indefinite indefinite
Plasma is the 4th state of matter – “ionized gas” like the sun
D. Kinetic Theory of Matter (2.1)
1. Gases possess the greatest amount of kinetic energy.
2. Two factors that determine the state of matter of a
substance: speed of the particles and the distance
between them.
3. These two factors contribute to the attraction between the
particles.
4. Substances change phase when they overcome these
attractions.
5. The overall kinetic energy (temperature) will remain
constant until the entire substance has completely
changed phase.
6. Heating Curve for Water
condensation
100
Vaporization
Liquid
freezing
0
(C)
Solid
melting
(boiling/evaporation)
Vapor
(gas)
E. Changes in Matter (2.1):
1. Physical Changes:

a. Do NOT change the identity of the substance.

b. Often change what the substance looks like.

c. Examples: cutting, dyeing, changes of state
States of Matter & Phase Changes
Solid
condensation
vaporization
Liquid
evaporation –at the surface
boiling - throughout
Gas
(Vapor)
States of Matter
Comparison of the three states of matter
Density = 1.00g/mL
Density = .92g/mL
2. Chemical Changes:
a. Alter the identity of the substance.
b. The new substance has different properties
than the original substance.
c. Examples of Chemical Changes: burning, rusting
d. Signs that a chemical change has occurred:
1. gas released (bubbles/odor/fizz/smoke)
2. color change (can be physical too)
3. formation of a precipitate (insoluble solid that
falls out of solution.)
4. temperature change  (can be physical also)
F. Law of Conservation of Matter (2.2):
Matter is neither created or destroyed
it just changes form.
G. Classification of Matter (1.3)
1. Pure substances: Substances that have a unique set of
physical and chemical properties.
a. Elements: The smallest part of an element is
an atom.
1. Cannot be separated into simpler substances.
2. Represented by symbols that have 1 or 2 letters.
Ex) K, Na, Au, Ag, Hg, Fe
(three lettered symbols are temporary)
3. Examples:
1
Atomic Number:
# of protons
Element Symbol: 1 or 2
letters (1st is a capital)
H
Hydrogen
Element Name
1.008
Atomic Mass:
(weighted average of
all an elements’s
isotopes)
b. Compounds:
1. Made up of 2 or more kinds of atoms
chemically combined in a fixed proportion.
2. Represented by formulas.
3. Examples: CO, CO2, H2O
2. Mixtures:
a. Heterogeneous Mixture: Visibly different
throughout. Will separate upon standing.
Ex) salad dressing (emulsion), chocolate
chip cookies, sand & water (suspension)
b. Homogeneous Mixture: The same
throughout. May be clear, will not separate.
Ex) Kool-aid (solution)
milk (colloid)
gold jewelry (alloy)
Examples of Alloys
Brass is an alloy of
copper and zinc.
Steel is an alloy of
carbon and iron.
Bronze is an alloy of
copper and tin.
Gold – Element & Alloys
Microscopic look at mixtures
Suspensions
Colloids
Solutions
ex) sand & water
ex) milk
ex) Kool-Aid
Alloys
ex) gold jewelry
H. Separating Mixtures (1.3)
1. Heterogeneous
Mixtures can be
separated by:
a. FiltrationMaterial remaining
on the filter paper is
called the residue.
The filtrate goes
through the filter
paper. Ex) sand & water
Separation of Homogeneous Mixtures:
a. Distillationseparates liquids
(and 1 solid) by
differences in
boiling point.
The remaining
material is called
the residue. The
material that goes
through is called
the distillate.
Ex) alcohol & H2O
Another Look at Distillation
• Distillation Demo
• A Closer Look at Distillation
Separation of Homogeneous Mixtures
b. Crystallization- Evaporate liquid and the solid
will crystallize. Ex) salt and water
c. Chromatography – used to separate
pigments and ink by differences in solubility
(density) on a strip of paper.
Ex) black ink - rainbow
Another look at Paper Chromatography
3. Separating Compounds:
a. Electrolysis – decomposes a compound into its
elements. Ex) water into H2 and O2