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physical science final review

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Physical Science
EOC Review
Marilyn Pendley, Instructor, CCCMC
Modified by R. Kittrell
Jan 2015 & 5Jan2016
1
2
Scientific Experimentation
controlled experiment
-Only one variable should be changed
at a time.
Manipulated (independent) variable –
changed by the experimenter.
Responding (dependent) variable – the
effect that is measured.
3
Law vs. Theory
• Develop a law
– Law: Summarizes the outcome of several
experiments that occur repeatedly and
consistently.
– Example: The spoiled food served at lunch
makes people sick with a stomachache.
• Develop a theory
– Theory: Explanation for why a law exists.
– Example: It is the bacteria in the spoiled food
that makes people ill.
4
Types of Measurements
1. Length
a. The distance from one point to another
point.
b. Base unit is the meter (m).
c. Tool is the metric ruler.
2. Volume
a. The amount of space a substance
occupies.
b. Base unit is the liter (L).
c. Tools: metric ruler for regular solids or
graduated cylinder for liquids.
5
3. Mass
a. The amount of matter in a
substance.
b. Base unit - kilogram (kg).
c. Tool is the balance.
4. Weight
a. A measure of gravitational force
on an object.
b. Unit is the newton (N).
c. Tool is the scale.
6
5. Time
a. How long an event takes to occur.
b. Unit is the second (s).
c. Tool is the clock (stopwatch).
6. Temperature
a. The amount of kinetic energy a
substance has.
b. SI unit is the Kelvin (K).
c. Tool is the thermometer.
7
7. Density
a. How compacted the matter is in a
substance.
b. Units can be g/mL, g/cm3, kg/m3.
c. Density is a derived unit (it is made
up of other types of measurement).
d. D = m / v
e. Objects float if their density is less
than the density of the fluid they are
in.
8
Matter
comes in 3
phases
Solid
Gas
Liquid
9
Solid
Definite
Shape
Definite
Volume
10
Liquid
Indefinite Shape
– takes the shape
of the container
Definite
Volume
11
Gas
Indefinite
Shape – takes
the shape of the
container.
Indefinite
Volume – can
expand and can be
compressed.
12
Plasma
•
•
•
•
•
Plasma: a high energy gaseous state of matter.
It is very unstable.
Particles are moving extremely fast, free energy
Most abundant phase of matter
Only present under extremely hot/energetic
situations
• Example: Sun
13
CHANGES IN STATE
• Melting: Solid to liquid
• Boiling: Liquid to gas
• Sublimation: Solid to gas
– The above three require input of energy
• Condensation: Gas to liquid
• Freezing: Liquid to solid
• Deposition: Gas to solid
– The above three release energy
14
Change of Phase
FIRST DO THIS Temperature Experiment By Clicking Here!
Phase
change
Phase
change
To Understand this Graph
CLICK HERE
15
PHYSICAL and CHEMICAL
PROPERTIES
Physical:
• Property of a substance that does not change
even if substance is altered.
• Examples- melting point, odor, color, etc.
Chemical:
• Property of a substance that can only be
observed because substance is changed.
• Examples- combustibility, reaction with acid
16
Chemical or Physical Change?
Chemical Change
Physical Change
• New substances formed
with new properties
• No new substances
formed
• Examples:
• Examples:
• Rusting
• Gas forming during a
reaction (bubbles)
• A precipitant forming
during a reaction
• Ice melting
• Water evaporating
• Dry ice subliming
into Carbon dioxide
• Salt or sugar
dissolving in water
17
18
CLASSIFICATION OF MATTER
19
ELEMENTS
• contain only one type of atom
• building blocks of matter
• 115 known elements today, 90 which
occur naturally
• Found on periodic table
– The first letter is always capitalized, the
second letter is always lower case
• Fluorine is F, not f
• Cobalt is Co, not CO (which is carbon monoxide)
20
Compounds
Compounds - 2 or more elements
chemically combined to form a new
substance with new properties
Properties – The way a chemical
substance looks and behaves
21
Mixtures and Pure Substances
– A mixture has unlike parts and a composition
that varies from sample to sample
• A heterogeneous mixture has physically distinct
parts with different properties.
• A homogeneous mixture is the same throughout
the sample
– Pure substances are substances with a fixed
composition
22
23
Electron_______
Cloud is a visual model
An _________
of the most likely locations for electrons in
an atom.
www.unitedstreaming.com – Physical Science – Elements, Compounds, and Atoms
An Orbital is a region of space around the nucleus where an electron is likely to be found.
* An electron cloud is a good approximation of how
electrons behave in their orbitals.
24
Lewis Dot Diagram
•An electron dot diagram uses
the symbol of the element and
dots to represent the outer level
electrons.
•Electron dot diagrams are used
also to show how the electrons
in the outer energy level are
bonded when elements combine
to form compounds.
25
Atom
the smallest particle making up elements
26
Atomic Structure Basics:
• Protons: positively charged
particles, weighing 1 atomic
mass unit (1.67x10-24 grams)
and located in the nucleus.
• Neutrons: neutrally charged
particles, weighing
approximately 1 atomic
mass unit and located in the
nucleus.
• Electrons: negatively
charged particles , weighing
zero atomic mass units,
located in orbitals of the
energy levels found outside
the atomic nucleus
27
Atomic Number:
• The number of protons • Play the Name the
in an atom determines
Atom Game at:
what element it is.
• http://www.learner.org
• Add or subtract even
/interactives/periodic/b
one proton from an
asics_interactive.html
atom of any element
and you no longer have
the original element in
any form. Now you have
a different element!
28
Drawing an Atom of Carbon
6
C
12.011
Atomic # = # of p+ and # of eCarbon has 6 p+ and 6 e-
Atomic Mass minus Atomic # = # of n0
Carbon has 6 n0
29
Drawing an Atom of
Carbon
eee-
6 p+
6 n0
e-
ee30
Periodic Table Basics:
Essential Question: What are Horizontal Rows called?
Answer: PERIODS
31
Electron Configuration
• The “Period” number is
equal to the number of
energy levels in an atom
• Remember:
The number of
electrons are equal to
the number of protons
in a neutral atom
32
What are Groups on the Periodic Table?
Essential Question: Groups are also known as Families of Elements.
They share chemical properties. WHY?
Answer: They have the same number of outer shell electrons.
33
Electron Configuration
• For Groups IA – VIII the
group numbers are
equal to the number of
outer shell electrons or
valence electrons
• Group “IA” has ONE
valence electron
• Group “IIA” has TWO
valence electrons; etc.
34
Name that GROUP:
The Alkali Metals
IA = one outer shell electrons
therefore Oxidation state?
+1
35
Name that GROUP:
The Alkali Earth Metals
IIA = two outer shell electrons
Oxidation state?
+2
36
Name that GROUP:
The Noble Gases
VIIIA = eight outer shell electrons (except Helium which has 2 but is FULL)
therefore Oxidation state?
NOT!
37
Name that GROUP:
The HALOGENS
The Salt Formers
VIIA = SEVEN outer shell electrons
therefore Oxidation state?
-1
38
Name that GROUP:
The Transition Metals
B series = usually 2 or 3 outer shell electrons
therefore Oxidation state?
+2 or +3
39
Criss-Cross Method
• Determine the charges/oxidation #’s for each
element.
• By criss-crossing the charges of the elements
you can easily write the chemical formula
• Example:
Hydrogen + Oxygen
– H + O  IONS = H+1 + O–2
– Criss cross the oxidation #
• just the numbers - not the + / - signs
– Write the numbers as subscripts
• bottom right of symbol
Criss Cross Method
This becomes
H+1
O-2
CrissCross the numbers
H2O1
Final:
H2O
• Where is the 1 in the final formula?
Criss-Cross Method
e-
This becomes
e-
H+1
O-2
CrissCross the numbers
H2O1
Final:
H2O
• Where is the 1 in the final formula?
Criss-Cross Method - -You Try it!
Mg + O
Ca + P
K+S
C+H
As + S
C+O
Criss-Cross Method
You Try
1.
2.
3.
4.
5.
6.
Mg + O
Ca + P
K+S
C+H
As + S
C+O
 Mg2O2  MgO
 Ca3P2
Just like with
Fractions in
 K2S
math the
 CH4
Numbers will
reduce!
 As2S3
 C2H4  CO2
Criss-Cross & Polyatomic Ions
• Sodium + Sulfate
– Na + SO4
– Na+1 + (SO4)-2
Do the Criss-Cross
Na2(SO4)1
Final: Na2(SO4)
Chemical Bonding:
• Three types of bonding
Game: Ionic Bonding
• Ionic
• Covalent
• Metallic
Bonding Animations and short clips
AWESOME MOVIE ON BONDING
30 minutes long
46
Ionic Bonding
• Ionic Bonds: between oppositely charged atoms;
usually on opposite sides of the periodic table
(nonmetal and a metal)
• transfer electrons
• form networks, not molecules
• conduct electricity
Covalent Bonds
• Covalent Bonds: share electrons; usually
between 2 elements close on the periodic table
(2 nonmetals)
– nonpolar covalent bond: e- shared equally
– polar covalent bond: e- shared unequally
Metallic Bonding
• “sea of electrons”: electrons can “float” freely
between atoms; allows metals to conduct
electricity well
Rules for naming and
writing chemical formulas
1. Metal name comes first
2. Change the ending of the second element to
“ide”
• If you have two nonmetals, use the prefixes:
Mono – 1
Penta - 5
Di - 2
Hexa - 6
Tri - 3
Hepta - 7
Tetra – 4
Octa - 8
50
Which of the following is the correct name
of a combination of sodium and iodine?
• a) sodium chloride
• b) sodium iodide
• c) sodium iodine
• d) iodine sodium
51
Transition Metal Naming
• Transition metals show their charges as Roman
Numerals because they can change charge!!
FeO = Fe+2 + O-2
Iron (II) Oxide
Fe2O3 = Fe+3 + O-2
Iron (III) Oxide
53
Chemical Reactions Types
• Combustion: ALWAYS has O2 as a REACTANT!
– AB + O2
AO + BO
• Single-Replacement (single-displacement):
• AX + B
A + BX
• Double-Replacement (double-displacement):
• AX + BY
AY + BX
54
Types of Chemical Reactions.
Type of
Reaction
Synthesis
Decomposition
Definition
 Equation
Two or more elements or
compounds combine to
make a more complex
substance
A + B → AB
Compounds break down
into simpler substances
AB → A + B
Single
Replacement
Occurs when one element
replaces another one in a
compound
Double
Replacement
Occurs when different
atoms in two different
compounds trade places
AB + C → AC + B
AB + CD → AC + BD
A = Red B = Blue C = Green D = Yellow
Identifying Chemical Reactions
Use colored pencils to circle the common atoms or compounds in
each equation to help you determine the type of reaction it
illustrates. Use the code below to classify each reaction.
S = Synthesis
D = Decomposition
____ P +
O2 → P4O10
____ HgO → Hg
____ Cl2 +
+
SR = Single Replacement
DR = Double Replacement
____ Mg + O2
O2
NaBr → NaCl + Br2
→
____ Al2O3
MgO
→ Al + O2
____ H2 + N2 → NH3
____ Na
____ HgO
+ Br2
→ NaBr
____ CuCl2 + H2S →
+ Cl2 → HgCl + O2
____ KClO3 →
KCl +
____ BaCl2 + Na2 SO4 →
O2
NaCl +
____ C +
____ S8
BaSO4
+
H2
→
F2 →
CuS + HCl
CH4
SF6
58
Solubility
59
Acids & Bases
• The strength of an acid or base depends on how
many acid or base particles dissociate into ions
in water.
• Strong Acid/Base
- +
– 100% ions in water
– strong electrolyte
– HCl, HNO3, NaOH, LiOH
•
Weak Acid/Base
• few ions in water
• weak electrolyte
• HC2H3O2, NH3
- +
60
pH Scale
• pH
– a measure of the concentration of H3O+ ions
in solution
– measured with a pH meter or an indicator
with a wide color range
IsotopesForms of an element
with different numbers
of neutrons (different
masses)
Isotopes of Hydrogen
Protium- A#1 M#1 #N=0
Deuterium- A#1 M#2 #N=1
Tritium- A#1 M#3 #N=2
62
More Isotope stuff…
A
Mass Number
Z
Atomic Number
1
1
2
H
1
235
92
U
X
Element Symbol
3
H (D)
1
238
H (T)
U
92
63
Radioactive Decay
Radioactive decay results in the emission [or release] of
either:
• an alpha particle (a),
• a negative beta particle (electron) (b-),
• a positive beta particle (positron) (b+),
• or a gamma ray (g).
In a nuclear reaction the MASS and ATOMIC NUMBER
must be the SAME on both sides of the equations
Alpha Decay
An alpha particle is identical to that of a helium nucleus.
It contains two protons and two neutrons.
A
X
Z
A-4
4
Y
He
+
Z-2
2
unstable atom
alpha particle
more stable atom
Beta Emission
A beta particle is a fast moving electron which is
emitted from the nucleus of an atom undergoing
radioactive decay.
Beta emission occurs when a neutron changes into a
proton and an electron.
A
X
Z
A
Y
+
Z+1
proton stays
in nucleus
0
e
-1
beta particle
(electron)
Gamma Decay
• When atoms decay by emitting a or b
particles to form a new atom, the nuclei
of the new atom may still have too much
energy to be completely stable. These
unstable atoms will emit gamma rays to
release that energy.
• There is no change in mass or atomic
number
A
X
Z
A
Z
X +
g
0
0
Decay Summary
Reaction
What happens?
Alpha Decay
a
Lose Helium Nucleus
Beta Decay
b-
Lose electron from nucleus
(neutron turns into proton)
Gammy Decay
g
Mass #
Atomic #
-4
-2
No change
+1
Emit high energy gamma ray No change
and either a or b particle
No
change
Test questions may involve
graphs like this one. The
Most common questions are:
"What is the half-life of this
element?"
Just remember, that at the end
of one half-life, 50% of the
element will remain. Find 50%
on the vertical axis. Follow the
blue line over to the red curve
and drop straight down to find
the answer:
The half-life of this element is 1 million years.
Another common question is:
"What percent of the material
originally present will remain
after 2 million years?"
Find 2 million years on
the bottom, horizontal
axis. Then follow the
green line up to the
red curve. Go to the left
and find the answer.
After 2 million years 25% of the original material
will remain.
Nuclear Energy Essential Questions:
• Why is it worth the
RISK??
• Tremendous
OUTPUT of
ENERGY!!
• Fission or Fusion?
•Fission! Atoms of
U-235 are split
•Use the link to see how Nuclear Fusion works:
•Fusion! Atoms are
joined or fused
together.
http://science.howstuffworks.com/fusion-reactor.htm/printable
71
Types of Energy
• Mechanical Energy
– Kinetic (motion) and Potential (stored)
• Heat Energy
• Chemical Energy
• Nuclear Energy
• Electromagnetic Energy
– Light, Sound, Electricity, Magnetism
72
73
Heat energy:
• Direction of Energy Flow?
• HOT toward COLD
74
Calculating Q
Q= Mass (m) X DT (change in temp) X Cp (Specific Heat)
Mass- in grams (or an equivalent unit to the mass in Cp)
DTemperature- (End Temp Co) – (Beg. Temp Co)
Cp- J/g X Co (a chart with CP values will be provided or you will be given the Cp
value in the problem)
Q Practice Problem
1. If the temperature of 34.4 g of ethanol increases
from 25 C to 78.8 C, how much heat has been
absorbed by the ethanol? (The Cp of Ethanol is
2.44 J/g . C).
Q= 34.4 g X (78.8 -25) X 2.44 J/g . C
Q= 4515.7568 J ~ 4.52 X 103 J
Why is subtracting end temp – beg temp SO
IMPORTANT?
To know if heat is being lost (-) or absorbed (+)
Three Ways to Transfer Heat
• Conduction
Direct contact
• Convection
Cyclic Movement
• Radiation
Through empty space
77
Dist. Vs. Disp.
• Distance
– Actual path that an
object takes
– Cannot be negative
• Displacement
– Straight line from start to
finish
– Can be negative or zero
Think about your charts made to calculate
distance and displacement on the grid.
Explain how an object can have a zero or negative displacement.
Speed and Velocity
• Speed: the rate at which an object changes
position
• m/s : SI unit for speed
Instantaneous vs. Average
• Instantaneous
Speed:
speed at a particular
point in time
• Average Speed:
speed taken over a
distance traveled
Ex: Speedometer of
a car
Ex: Calculating your
speed over an entire
trip
How is velocity different than speed?
• Velocity is speed with a direction.
Ex: traveling 60 km/hr North
Two ways to change velocity:
1. Change speed (speed up/slow down)
2. Change direction (turn)
Acceleration
• Acceleration: is the rate of change in
velocity
Acceleration = change in velocity
time
a = ve – vb
time
• SI unit of acceleration = m/s/s or m/s2
Ways to Change Acceleration
• Change Speed
• Change Direction
Can you have negative
acceleration?
Speed and Time Graphs
Forces
• A force causes an object
to move, accelerate,
change speed, or
direction
• The unit of force is the
Newton (N).
– 1 N = 1 kg x m/s/s
Balanced &
Unbalanced Forces
• Balanced forces –
opposite and equal forces
acting on the same object
– result in NO motion of
the object
• Unbalanced forces –
two or more forces of
unequal strength or
direction acting upon
on an object
– results in motion of
the object
Types of Forces
• Gravity
• Friction
• Fluid Pressure Forces
• Air Pressure
Falling Objects
• A falling object will accelerate
downward at 9.8 m/s/s (in a
vacuum). However, in real life air
resistance will gradually slow it
down.
• Terminal velocity is the top speed
reached by a falling object. At
terminal velocity air resistance is
equal to gravitational pull.
Circular Motion
• According to Newton's 1st
Law, an object will move in
a straight line unless a net
force causes it to do
otherwise.
• Therefore, an object
moving in a curved or
circular path, like a
tetherball, must have a
force pulling it in a circle.
Work
• Work is done on an object when a force is
exerted on an object that causes the object to
move some distance.
– No work without motion
– No work without force in the same direction
Direction and force
• Horse does not work on • Horse does work on the
the rider – force not in
cart - force and motion
same direction
in the same direction
Force on
person
Force on
cart
motion
motion
Calculating work
• Work =
Force X Distance
– Force units = Newton, N
– Distance units = meter, m
– Work units = Joule, J
• J = N*m
4. Calculating Work
4. A woman lifts her 100-newton child up one
meter and carries her for a distance of 50
meters to the child’s bedroom. How much work
does the woman do?
Work
100 N X 1 m= 100 N-m
(the 50 meter carry is not in
the upward direction the force
is applied)
Mechanical advantage
• Mechanical Advantage is used to determine if
using a simple machine would be better to
accomplish work than not using a simple
machine.
– Example- would it be better to dig a hole with
your hands or a shovel?
• If M.A. > 1 than using the simple machine was
beneficial.
• If M.A. < 1 than it would have been better to NOT
use the simple machine.
Mechanical advantage
• There are TWO ways to calculate Mechanical
Advantage:
– Ideal Mechanical Advantage (IMA) which uses distances
to determine.
– Actual Mechanical Advantage (AMA) which uses force to
determine.
The 6 Simple Machines
Movable Machines
Lever
Pulley
Non-movable Machines
Inclined Plane
Screw
Wheel and Axle
Wedge
What does a simple machine do?
• Make work easier by
• Changing the applied force
• Changing the distance over which the
force is applied
• Changing the direction of the effort force
What does a simple machine NOT do?
You cannot get more work output than work
input!
3 Classes of Levers:
Remember what is in the middle:
F- 1st Class-Fulcrum
nd
R- 2 Class- Resistance
E- 3rd Class- Effort
Transverse waves
A transverse wave is one in which the disturbance is
perpendicular to the direction of travel of the wave.
Examples: Light wave, waves on a guitar string.
Longitudinal Waves
Longitudinal wave is one in which the disturbance is parallel
to the line of travel of the wave.
Example: Sound wave in air is a longitudinal wave.
The Nature of Sound
Longitudinal Sound Waves
Sound in air is a longitudinal wave that is created by a
vibrating object, such as a guitar string, the human vocal
cords, or the diaphragm of a loudspeaker.
Constructive Interference of Sound
Waves
Wavelength = λ = 1 m
Path difference = 0
Destructive Interference
Wavelength = λ = 1 m
Path difference = λ/2= 0.5 m
Doppler effect
• Change in frequency and pitch of a sound.
• Due to the motion of either the sound source
or the observer.
• Listen!
Doppler effect of sound
Electromagnetic Waves
• Transverse waves without a medium!
• (They can travel through empty space)
• Electromagnetic waves travel VERY
FAST – around 300,000 kilometres per
second (the speed of light).
At this speed they
can go around the
world 8 times in one
second.
•
•
Waves or Particles?
Electromagnetic radiation has properties of
waves but also can be thought of as a stream of
particles.
– Example: Light
•
Light as a wave: Light behaves as a transverse wave
which we can filter using polarized lenses.
•
Light as particles (photons): When directed at a
substance light can knock electrons off of a substance
(Photoelectric effect)
Notice the wavelength is
long (Radio waves) and gets shorter (Gamma Rays)
Where is Magnetism Concentrated?
Magnetism is strongest at the
POLES
111
Magnetic Domains :
Not aligned:
Magnetic domains
are ALIGNED in a
permanent
magnet :
112
What happens if you cut a magnet in half?
113
Electromagnets:
• What Happens if you
increase the number
of coils in an
electromagnet?
• The magnet gets
STRONGER!
114
Get in line!
115
Ways to charge an object:
1. Conduction- direct touching
2. Induction- getting inside field but not
touching
3. Friction-rubbing two objects together
(forms static electricity)
116
Answer key:
A: PE = 40 J (since the same mass is
elevated to 4/5-ths height of the
top stair)
B: PE = 30 J (since the same mass is
elevated to 3/5-ths height of the
top stair)
C: PE = 20 J (since the same mass is
elevated to 2/5-ths height of the
top stair)
D: PE = 10 J (since the same mass is
elevated to 1/5-ths height of the
top stair)
E and F: PE = 0 J (since the same
mass is at the same zero height
position as shown for the bottom
stair
Note since
PEgrav = m *• g • h
Doubling of the height
will result in a
doubling of the
gravitational
potential energy.
• A tripling of the
height will result in a
tripling of the
gravitational
potential energy.
117
Physics Portion
• Make a given table that lists the information
you are given. BE SURE to include the item
you are to find!
• USE the Reference sheet! Find the equation
that fits what you have.
• Put the item you need to find on one side of
the equals sign.
• Add the other numbers and punch in the
calculator.
• Double check the answer from the calculator!
118
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