GHSGT Review Physical Science
CHEMICAL CONCEPTS
M atter: anything that has mass and takes up space elements pure substances compounds mixtures heterogeneous homogeneous one type of atom more than one type of atom solutions same throughout different parts are visible not held together by bonds held together by bonds mass- amount of matter in an object volume- the amount of space an object takes up
Density- mass divided by volume D=m/v
Weight- mass times acceleration due to gravity W=mg g= 9.81m/s 2
Type of properties What they describe
Physical Properties Describe what matter is
(like an adjective)
Chemical Properties Describe what matter does (like an adverb)
Examples
Color, density, hardness, mass, volume, boiling point, conductivity, malleability, melting point, odor, shape, weight
Reacts with oxygen,
Does not react with metals
Ability to burn, ability to corrode, reactivity with light
Type of Changes
Physical Change
Chemical Change
Definition Examples
Does not create a new substance Cutting paper
Phase changes
Tearing paper
Creates a new substance
Dissolving salt in water
Burning
Rusting

Temperature- the measure of how hot or cold something is
Melting point – the point at which a substance changes from a solid to a liquid
Boiling point- the point at which a substance changes from a liquid to a gas
Name
Melting
Phases changed
Solid to liquid
Heat transferred
Heat gained (heated)
Freezing
Vaporization
Condensation
Liquid to solid
Liquid to gas
Gas to liquid
Heat lost (cooled)
Heat gained (heated)
Heat lost (cooled)
Sublimation Solid to gas
ALL PHASE CHANGES ARE PHYSICAL CHANGES!
Mixtures are separated by Physical Changes!
Heat gained (heated)
Chemical Changes-
- makes a new substance
written as chemical equations
equations use symbols (for elements) and formulas (for compounds)
symbols for elements are found on the periodic table
reactants: the chemicals that do the reacting, the chemicals going into the reaction, written on the left of the arrow normally
products: the chemicals that are made during the reaction, the chemicals coming out of the reaction, written on the right of the arrow normally
Types of reactions:
Synthesis- makes a single product, more than one reactant (on the left) only one product (on the right).
Decomposition- breaking down a single reactant into multiple products, one reactant (on the left)
more than one product (on the right)
Single replacement- an element replaces another element in a compound, one element and a
compound on the left, different element and compound on the right
Double replacement- two compounds switch parts, two compounds on the left, two different
compounds on the right
Evidence of Chemical Reactions
1.
Color change
2.
Gas produced
3.
Precipitate
4.
Light given off
5.
Electric current produced
6.
Temperature changes on its own
Endothermic- heat is taken in from the surroundings, the container of the reaction will feel cool or cold to the touch
Exothermic- heat is given off from the reaction, container of the reaction will feel warm or hot to the touch
Common Chemical Reactions
1.
Combustion- Combining with oxygen rapidly
2.
Rusting- combining with oxygen slowly

3.
Neutralization- reaction between an acid and a base to form a salt and water
4.
Fermentation- partial breakdown of sugars by yeasts to produce carbon dioxide and alcohol, in the absence of oxygen
Naming Ionic Compounds
1.
Write the name of the positive ion without the word ion.
2.
Write the name of the negative ion without the word ion.
Naming Covalent Compounds
Some additional rules


mono
The element that comes first in the following list "goes" first.
B, Si, C, Sb, As, P, N, H, Te, Se, S, I, Br, Cl, O, F
H
2
O, which according to the rules should be called dihydrogen monoxide is always called water, and
NH
3
, or nitrogen trihydride, is always called ammonia
Naming Organic Compounds
Prefix
Meth-
Eth-
Prop-
But-
Pent-
Hex-
Hept-
Oct-
Non-
Dec-
Number of Carbons
1
2
3
4
5
6
7
8
9
10

Suffixes
All single bonds -ane
A double bond -ene
A triple bond -yne
Examples
Methane, Ethane, Ethene, Ethyne
Writing Balanced Equations
Law of Conservation of Mass- Matter cannot be created nor destroyed it can only change forms
- What goes in, must come out
Basis for Balancing equations
These numbers are found in a chemical equation:
 Subscripts
The small numbers to the lower right of chemical symbols. Subscripts represent the number of atoms of each element in the molecule.
 Coefficients
The large numbers in front of chemical formulas. Coefficients represent the number of molecules of the substance in the reaction.
The order in which the following steps are performed is important.
While shortcuts are possible, following these steps in order is the best way to be sure you are correct.
Types of Particles
Atoms- The smallest part of an element that can be identified as that element bonds)
Compound- substance made up of two or more elements chemically combined (held together by
Chemical bonds- force of attraction that hold atoms together (involves either sharing or transferring electrons)
All atoms want a full outer set of electrons. A full outer set consists of 8 electrons and is called an octet. Atoms form compounds to fill their outer set of electrons.
For some atoms, such as metals, it is easier for them to give up their 1 or 2 electrons in the outer shell and fall back on the full shell beneath those electrons. For other atoms, such as Fluorine, Nitrogen,
Oxygen, it is easier to take 1-3 electrons to fill their outer shell. Some atoms prefer to share electrons.
Some will do both. The noble gases such as Argon and Neon already have a full outer set of electrons and do not react.
Covalent Bonds- sharing electrons between two atoms
Molecules- smallest particle of a covalent compound
Ionic bonds- Transfer of electrons between two atoms
Formula unit- smallest unit of an ionic compound

Ion- a charge particle formed by the loss or gain of electrons
Cation- positively charged ion formed by losing one or more electrons
Anion- negatively charged ion formed by gaining one or more electrons
Elements made up of atoms.
Compounds made up of molecules (covalent) or ions ( ionic).
Atoms
- made up of protons, neutrons, and electrons
has two regions: nucleus and electron cloud
Nucleus- dense center region of the atom, positively charged, contains protons and neutrons, contains nearly all the mass of the atom
Electron cloud- region around the nucleus where there is a good chance an electron might be found
Name
Proton
Neutron
Electron
Charge
+1
0
-1
Relative Mass
1
1
0
Location
Nucleus
Nucleus
Outside of Nucleus (electron cloud)
Atomic number- the number of protons in an atom
- all atoms of an element have the same atomic number
- the element an atom belongs to is determined by the atomic number
- in a neutral atom (no charge) the number of electrons is the same as the atomic number
Mass number- The number of protons PLUS the number of neutrons in an atom
Calculating the number of neutrons in an atom:
Mass number – Atomic number= Number of neutrons
Mass number is found on the periodic table…. It is the number with the decimal.
Atomic number is also found of the periodic table…. It is the whole number without a decimal.
Isotope- has the same number of protons but a DIFFERENT number of NEUTRONS.

Isotope
Atomic Number (protons)
Mass Number (protons and neutrons)
Carbon- 12
6
12
Carbon-14
6
14
Neutron Number
Calculations
6
12 - 6 = 6
8
14 – 6 = 8
Protons, neutrons, and electrons are made up of even smaller particles called quarks and leptons.
History of the Atom
Person
Democritus
John Dalton
Where he was from and when
Ancient Greece
England 1803
England 1897
England 1914
What they did
Named the Atom
Proposed an “atomic theory” of solid atoms based on mass
Discovered the electron J.J. Thomson
Ernest Rutherford
England 1932
Denmark 1922
Discovered the proton using his famous gold foil experiment
Discovered the Neutron James Chadwick
Neils Bohr Proposed that electrons orbited the nucleus like planets orbit the sun
Dalton’s Theory
1.
All elements made up of atoms.
2.
Atoms of the same element have the same mass.
3.
Atoms of different elements have different masses.
4.
Atoms combine in small whole number ratios.
He only got 2 of the four right. 1 and 4 are correct. 2 and 3 are incorrect. Atoms of the same element can have DIFFERENT masses and are called
ISOTOPES.

Periodic Table of the Elements
- contains 112 known elements
created by Russian chemist Dmitri Mendeleev
listed in order of their Atomic Number (number of protons)
vertical columns called families and have similar chemical properties o families have the same number of electrons in their outer shell
rows are called periods and have the same number of occupied energy
levels.
Periodic Law- when elements are put in order of their atomic numbers (number of protons) there is a repetition of similar properties as you move through the chart
Metals
- Shiny
- good conductors of heat and electricity
- malleable (can be hammered into thin sheets)
- ductile (can be drawn into wire)
- lose electrons in reactions
- less than 4 electrons in their outer shell
- found on left side of the periodic table
Nonmetals
dull
brittle (break easily)
gain electrons in reactions
have 4 or more electrons in their outer shell
on the right side of the periodic table
Metalloids
have properties of both metals and nonmetals
along the stair step line that separates metals and nonmetals
Alkali Metals
far left side vertical column on the periodic table
soft
silvery white
highly reactive
never found as elements in nature
only have one electron in their outer shell
can react explosively with water
Alkaline Earth Metals
2 electrons in outer shell
found in minerals in the earth’s crust
not as reactive as Alkali Metals
in second column from the left
Transition Metals
metals in the 10 shorter columns in the middle of the periodic table
usually have 2 outer shell electrons
form brightly colored compounds

Rare Earth Metals
Lanthanide series
Actinide series
At bottom of chart
All actinides are radioactive
All elements after uranium are synthetic or man-made
Halogens
second column from the right
7 outer shell electrons
react with metals to form salts
most reactive nonmetals
Noble Gases
- Vertical column on the far right of the periodic table
have full outer shell of electrons
do not react normally
Kinetic Theory
All matter is made of atoms and molecules that act like tiny particles.
These tiny particles are always in motion. The higher the temperature the faster the particles move.
At the same temperature, more massive (heavier) particles move slower than less massive
(lighter) particles.
Solids-
rigid structure
do not take the shape of their container
molecules vibrate in their positions but do not move past each other
Liquids
take the shape of their container
molecules can move past each other
can flow
have freedom of movement
Gases
can fill their container
spread in all directions
molecules move very fast and are very far apart
State of Matter
Solid
Liquid
Shape
Definite
Not definite
Volume
Definite
Definite
Gas Not definite Not definite
Viscosity-the attraction between molecules of a liquid, determines how fast or slow something flows
Pressure- force per unit area, or force divided by area
Solutions-
homogeneous mixtures

same throughout
made up of two parts
Solute- the substance being dissolved
Solvent- the substance doing the dissolving
Solubility- the ability of a substance to dissolve in another substance
Acids and Bases
Acids
Substance that produces Hydrogen ions (H + ) in solution
Hydrogen combined with one or more nonmetals
Vinegar, citrus fruits, tomatoes, tea, sodas
Sour taste
Turn blue litmus red
pH less than 7
can neutralize bases
Bases
substance that produces hydroxide ions in solution (OH )
metal combined with a hydroxide
slippery
taste bitter
turn red litmus blue (base- blue- bitter- remember your b’s)
pH greater than 7
neutralize acids
Neutralization reactions- reaction between an acid and a base producing a salt and water pH scale – how basic or acidic something is
7 is neutral example: pure water less than 7- acidic hydrochloric acid, sodas greater than 7- basic baking soda, ammonia
Indicators- change color in different pH solutions
Indicators tell the pH of a solution
Examples: phenolphthalein and litmus
RADIOACTIVITY
Nuclear changes- changes in the nucleus of an atom
3 Types of Nuclear Reactions
Nuclear Fission
Splitting the nucleus into two smaller nuclei
Nuclear chain reaction- the splitting of the first nucleus releases particles which strike nearby nuclei, and cause them to split. This continues until there are no more nuclei to split or all the particles are absorbed.
The splitting of a nucleus releases a great deal of energy
Uncontrolled chain reactions are used in nuclear bombs
Controlled nuclear fission is used to create electricity
Nuclear Fusion

Two smaller nuclei join together to create a larger nucleus
Occurs in stars and the sun
Radioactive Decay
Spontaneous breakdown of a nucleus
Releases particles or rays and a lot of energy
3 types of decay
Alpha decay
Positively charged
Release of a helium nucleus from the nucleus undergoing decay (2 protons and 2 neutrons)
Easiest radiation to protect yourself from
Stopped by a sheet of paper
Beta decay
Negatively charged particle
High speed electrons emitted from nucleus
Can be stopped by a thin sheet of aluminum foil
Gamma decay
High energy radiation
No particle emitted just energy
Can penetrate several feet of concrete
Half- Life
Amount of time it takes for half of a sample to undergo radioactive decay
Number of Half lives
1
2
3
4
PHYSICAL CONCEPTS
Force
a push or pull on an object
mass times acceleration
½
½ x ½
½ x ½ x ½
½ x ½ x ½ x ½
Amount of sample remaining
½ sample remaining
¼ sample remaining
1 /
8
sample remaining
1 /
16
sample remaining
Types of Forces
Gravitational force- a universal force between two objects, all objects exert gravity, but it may not be measurable
Weight- measure of the force of gravity on an object
Gravity is dependent on the size of the objects and the distance between them
The further apart two objects are the more the gravity between them decreases
Electromagnetic Force- caused by positive and negative electrical charges in matter
Electric forces- forces between electric charges
Magnetic forces- forces between magnetic charges
Opposites attract
Like charges repel
Nuclear Forces- forces in an atom’s nucleus that hold the protons and neutrons together
Frictional Forces- forces that oppose the motion of two objects in contact
sliding friction occurs when a solid surface slides over another solid surface

rolling friction occurs when an object rolls across a solid surface, rolling friction is less than sliding friction
static friction occurs between the surfaces of two objects that touch but do not move
Net force- combination of all the forces on an object
20 N
-20 N
Net force = 20 N + -20N
Net force = 0 N
Balanced Forces- net force equal to zero
Unbalanced Forces- net force not equal to zero
Unbalanced forces cause an object’s motion to change
Speed- how fast something goes
Average speed = distance divided by time
Velocity= speed AND direction
Momentum is how hard something is to stop
Momentum = mass times velocity p = mv (p = momentum)
Acceleration= change in velocity over time
A = v f
– v i
/ t
F= ma
Unit of force is the Newton (N)
Newton's
Laws of
M otion
Newton's
1st Law of
M otion
Newton's
2nd Law of
M otion
Newton's
3rd law of motion
F= ma an object at rest will stay at rest and an object in motion will remain in motion until a force acts up on it for every action there is an equal but op p osite reaction inertiaresistance to change in motion

A man pushes a 50 kg box across a horizontal cement surface, causing the box to accelerate at 0.50 m/s 2 .
If he pushes with a force of 40 N, what is the frictional force acting between the box and the floor?
Net force= mass times acceleration
F
NET
= ma
F
NET
= (50 kg)(0.50m/s 2 )= 25 N
F friction
= F man
–F net
= 40 N – 25 N= 15 N
Work
Work= force times distance W=fd
If the force doesn’t act over a distance then no work is done
Unit of work is the Joule (J)
Power
Rate at which work is done
Power = work divided by time P = w/t
Unit of power is the Watt (W)
Simple Machines
Make work easier or faster
Do NOT decrease the amount of work done
Work with one movement
6 types
Lever
Pulley
Wheel and axle
Inclined plane
Screw
Wedge
Levers
3 Types
1 st class lever fulcrum in the middle
2 nd class lever load is in the middle
3 rd class lever effort is in the middle
Inclined planes- ramps
Pulleys- wheels with a rope wrapped around them
Screws- an inclined plane wrapped around a cylinder
Wheel and axle- a wheel attached to a rod
Wedge –two inclined planes back to back

Effort force- the force applied
Work input- work done on a machine
Effort distance- the distance through which the effort force acts
W i
= F e
x d e
Work output – the amount of work the machine does
Resistance force – the force applied by the machine
Resistance distance – the distance the resistance force moves through
W o
= F r
x d r
Mechanical advantage- the number of times the machine multiplies the effort force
MA= F r
/ F e or MA = d e
/ d r
Efficiency- a comparison of the work output to the work input, written as a percentage
E=( W o
/ W i
) x 100%
Efficiency can never be more than 100%
ENERGY
Law of Conservation of Energy
Energy can never be created nor destroyed, it only changes forms.
Types of energy
Light (Radiant)
Electromagnetic
Sound
Heat (Thermal)
Electrical
Nuclear
Chemical
Mechanical
Mechanical energy- the energy of objects
2 types of mechanical energy
Kinetic energy- energy of motion
KE= ½ mv 2
m = mass
v = velocity
Gravitational Potential energy- energy of position
PE = mgh m = mass g = gravity = 9.8 m/s 2 h = height above ground
Energy Sources
Fossil Fuels ( need to reduce dependence)
Geothermal (heat from inside the earth)
Hydroelectric (using running water to make electricity)

Nuclear
Solar (from the sun)
Wind
Heat transfer
The movement of thermal energy from warmer to cooler materials
3 ways heat transfer occurs
1.
Conduction- heat transferred by two objects in contact with each other a.
Conductors- materials that allow heat to transfer easily b.
Insulators- materials that slow the transfer of heat
2.
Convection- heat transferred by the movement of fluids
3.
Radiation- heat transferred through electromagnetic waves, can move through empty space, how the sun’s energy gets to earth
Wave
A disturbance that repeats the same cycle of motion
Transfers energy
Transverse wave particles move at right angles to the direction of the wave
(particles move up and down) example: ocean waves
Longitudinal waves particles move in the same direction as the direction of energy ( move back and forth)
Waves
Crest- highest point of a transverse wave
Trough- lowest point of a transverse wave
Amplitude- the distance from the line of origin to a crest or trough
Proportional to the amount of energy in a wave
Wavelength- distance between two consecutive crests or troughs of a wave
Symbol lambda (
 to represent wavelength
Frequency- the number of complete waves that pass a point in a certain amount of time
Measured in Hertz (Hz)
Period- the amount of time it takes for one wave to pass a point
Measured in seconds
Speed- how fast the wave is moving
Wave speed = frequency times wavelength
V = f x


4 basis wave interactions
1.
Reflection- the bouncing back of a wave when it strikes a boundary a.
Law of Reflection- the angle at which the wave bounces off a boundary is equal to the angle at which the wave struck the boundary
2.
Refraction- The bending of a wave when it passes from one medium to another, this occurs due to a change in speed
3.
Diffraction occurs when a wave passes through an opening and spreads out
4.
Interference- when two or more waves occupy the same spot and combine to produce a single wave a.
Constructive interference- when the waves meet crest to crest or trough to trough and make a larger wave b.
Destructive interference when waves meet crest to trough and make a smaller wave c.
Total destructive interference- when two waves with the same amplitude meet crest to trough and cancel each other out completely
Electromagnetic Waves
All light waves are part of the electromagnetic spectrum.
Electromagnetic waves produce both electric fields and magnetic fields.
All electromagnetic waves are transverse waves.
All electromagnetic waves travel at the same speed in a vacuum (3.0 x 10 8 m/s)
The full range of frequencies and wavelengths is called the electromagnetic spectrum.
(left to right increasing wavelength, decreasing frequency)
Visible light- the part of the electromagnetic spectrum that can be seen by the human eye
Roy G. Biv Red Orange Yellow Green Blue Indigo Violet
Polarized light- light that has been filtered to only vibrate in one direction
Mirrors-
Virtual images- appear to be behind the mirror, cannot be shown on a screen
Real images- appear in front of the mirror, light rays actually meet there, can be shown on a screen
Plane mirror and convex mirrors form only virtual images
Concave mirrors form both real and virtual images.
Concave- mirror that caves in

Convex- mirror that bows out
Concave :
Convex:
Plane mirror:
Lenses refract light rather than reflect it.
Converging lens:

Diverging lens:
Converging (convex lenses) form real and virtual images.
Diverging (concave lenses) form virtual images.
Lenses are used to magnify objects and correct vision problems.
Sound
Form of energy that causes objects to vibrate
Longitudinal waves make up sounds
Compression- area where the particles are closer together (same as a crest in a transverse wave)
Rarefaction- area of the wave where the particles are farther apart (same as a trough in a transverse wave)
Loudness- the intensity or amount of energy in the wave
Pitch- the frequency of the wave (determines how high or low a wave sounds)
Greater the frequency the higher the pitch
Lower the frequency the lower the pitch
Doppler Effect occurs when a sound source moves, causing the pitch to increase as the source moves closer, and causing the pitch to decrease when the source moves away (remember how an ambulance sounds when it is moving toward you and away from you)

Timbre- sound quality, caused by the blending of various pitches or tones
Sound that is pleasing to the ear is called music
Sound that is not pleasing to the ear is called noise
Sound travels fastest through solids, next fastest through liquids, and slowest through gases.
Sound doesn’t travel at all through the vacuum of space (where there is no medium or material to carry it, not to be confused with a vacuum cleaner… sound travels quite well in a vacuum cleaner just ask any indoor pet.)
When sound waves hit another object, they can be absorbed, travel through the object, or they can be reflected.
Reflected sound waves are called echoes.
Electricity
Static electricity- the accumulation of like charges
Cause by
Friction
Rubbing two objects together, like a balloon and your hair
Conduction
Transfer of charges from one object to another by touching the objects together
Induction
A charged object is brought near to an uncharged object, since opposite charges attract, the charges in the uncharged object move in such a way as that the charges opposite the ones on the charged object are closer to the charged object
This causes the uncharged object to behave as if it is charged
Law of Electric Charges – opposites attract, like charges repel
Electric fields- area in which the electric force is noticeable
Strength of electric field depends on the distance from the charged particle
Electric discharge- when electric charges leave an object that has static electricity built up
Electric current- the flow of electric charges
Electric current is produced by the flow of electrons
Electric current only flows in circuits
Circuit- a complete, closed path for electron flow
5 ways to produce an electric current
1.
Electromagnetic generators- turn a coil of wire through a magnetic field (
Electromagnetic Induction), as the coil rotates, the flow constantly reverses directions creating an alternating current (AC), this is how electricity is produced for our homes
2.
Electrochemical cells- also called batteries, produce electric current from chemical reactions, produces direct current (DC)
3.
Solar cells- produce electricity from light
4.
Thermocouples- produce electricity from heat
5.
piezoelectric cells produce electricity when pressure is applied to certain crystals
Electric Current- when electrons flow through a wire, measured in amperes (A).

Potential Difference- the electrical potential energy between two places in a circuit, measured in Volts (V) also called Voltage
Resistance- The opposition to the flow of current measured in ohms (

).
Good conductors such as copper have low resistance
Resistance in wires is depends on thickness, length, and temperature
Ohm’s Law
V=IR
Voltage= current times resistance
Series circuit- charges only have one path to flow through
If one light goes out they all go out
R total
= R
1
+ R
2
+ R
3
….
Parallel Circuit- charges have more than one path to flow through
If one light goes out, the others stay on
R total
= 1 /
R1
+ 1 /
R2
+ 1 /
R3
…..
Series parallel circuits have some elements in series and some in parallel

Magnetic field- region around a magnet or current carrying wire where magnetic forces are noticeable
Magnetism- the force of attraction or repulsion due to electron motion
Magnets have 2 poles a north and a south
Like poles repel
Opposite poles attract
Magnetic domains- groups of atoms with magnetic poles aligned
If most of the domains line up the material is considered magnetized
Electromagnet- a coil of wire wrapped around a iron bar, with electric current flowing through the wire
Generators use electromagnetic induction to create electricity
Electromagnetic induction- a wire turning through a magnet to produce electricity