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Physical Science Review
for the NC final exam
What is determined by the
distance from the starting point
in a straight line?
Displacement
Follow-up Question:
List 2 things that make
determining the value of
displacement different from
determining distance values.
The stationary object that is
used to determine if an
object has motion.
Reference point
What is the equation used to
determine the speed of an
object?
V= d
t
Follow-up Questions:
a) What do the v, d, and t symbols represent in
the formula?
b) What other value can this formula
represent, and how is this value different
from speed.

What is the equation used to
determine the acceleration
of an object?
a = ( Vf - Vi )
t
Follow-up Questions:
a) What is meant by each of the variables in
the equation?
b) When would the Vf value be zero?
c) When would the Vi value be zero?
What are 2 ways that you
could change the
acceleration of an object?
You could change the speed of the
object or you could change the
direction of the object.
B
C
D
A
A)What
A?
B) What
B?
C)What
point
is represented by the velocity/ time line at point
is represented by the velocity/ time line at point
is represented by the velocity/time line at
C?
Point A = the object is accelerating.
This is a constant acceleration as the distance
increase occurs at the same distance for each
same time interval.
b)
Point B = Since the velocity (speed) does not
change, but the time does the object is
traveling at a steady speed.
c)
Point C = Since the velocity at point C goes
down the speed is decreasing (is negative).
d) Point D = The upward J shape on the velocity
/ time graph shows a great jump/increase in
velocity over a short time so ( acceleration is
increasing)
a)
What is the equation for
momentum?
P = mv
m= mass,
v=velocity
Explain how a less massive
object can have the same
momentum as a more
massive object.
The less massive object can be traveling at
a much faster rate than the more massive
object.
Ex: 10 kg object moving at 10 m/s=
a momentum of (10x10=100 kg m/s)
20 kg object moving at 5 m/s =
a momentum of (20x5= 100 kg m/s)
They both have the same momentum.
Can an object have a
momentum of zero?
Yes, it the object is not moving
(at rest) the velocity (speed)
would be zero.
If p=mv and v=o then no
matter how big the mass,
p=0.
Why would you weigh more
on Earth than you would on
the moon?
(Explain using an equation)
Because the formula for weight is
Fg = mg
( Weight= mass x gravitational pull )
Because the mass of the Earth is greater
than the mass of the moon it has a greater
gravitational pull. If the mass (the
amount of matter in an object) remains
the same and the “ g “ increases so does
the weight.
What is it called when an object
falls with only the force of
gravity acting on it?
Free fall
Follow-up Question:
What is the rate (velocity) at
which objects on Earth
experience free-fall.
When does a falling object
reach terminal velocity?
When the acceleration of an object
in free fall is equal to the
upward force of air resistance.
This results in an acceleration of
zero.
Friction is a force that opposes the
motion of an object.
List the type of friction in each of
the following examples:
a)
b)
c)
d)
A fish swimming in a stream.
A car wheel as a car travels down
the road.
A plate sitting on the table.
A wooden crate pushed across the
floor.
A)
B)
C)
D)
The fish is moving in water (a fluid) and
therefore the water is exerting fluid
friction on the fish.
The car wheel is round and thus as it
moves will exhibit rolling friction.
The plate is sitting (thus at rest not
moving) on the table. It is therefore
encountering static friction.
The wooden crate flat surface is being
pushed across the floor. The crate bottom
is therefore sliding across the floor and is
experiencing “sliding friction”
Explain why Newton’s 1st law
of motion is also called the
law of inertia.
Newton’s 1st Law: An object at
rest, (or an object in motion),
will continue to remain at rest,
(or in motion) unless acted on
by an unbalanced force.
Inertia= the tendency of an object
to resist change.
This means that if it is at rest it
wishes to remain at rest. If it is
in motion is wishes to continue
the motion.
How does an applied force
on an object affect the rate
at which the object
accelerates?
If the same force is applied on the objects
of different masses it will cause them to
move at different rates of acceleration.
Ex: 20 N of force is applied to two objects.
One object is 10 kg, the other has less
mass at 5kg. When the same force (20N)
is applied to both the larger object
moves less (20N = 10 kg x 2 m/s2 )
than the smaller object (20N = 5 kg x
4m/s2)
What is the equation
associated with Newton’s
nd
2 law of motion?
F=mxa
Which one of Newton’s
laws of motion is
demonstrated by firing a
rifle?
Newton’s 3rd law of motion.
Action-Reaction law
(For every action there is an equal and
opposite reaction.)
The gunpowder explodes the hot gases
expand outward allowing the rifle to
push the bullet. The bullet pushes
backwards upon the rifle.
Why does the bullet move out of the gun
barrel if the forces are equal?
- Although the forces are equal, they are acting
on different objects. The bullet will accelerate
from the gun barrel because the mass of the
bullet is less than the mass of the rifle.
Matter is classified as either a
pure substance or a mixture.
a) List the 2 types of pure
substances.
b) List the 2 types of mixtures.
Pure Substances include:
Elements (found on the periodic table)
Compounds
A)
Types Of Mixtures:
Heterogeneous (mixtures made of different things
that have different properties because the
mixture is not uniform throughout)
Homogeneous (mixtures in which the parts are
mixed and distributed in a uniform matter
where all parts of the mixtures appear to contain
the same material).
B)
List the following as either a pure
substance ( P ) or a Mixture (M)
A)
B)
C)
D)
E)
F)
Granite rock
Air
Salad
Blood
Ink
Oil/vinegar salad dressing
A)
B)
C)
D)
E)
F)
Granite rock ( Hetero)
Air
(Homo)
Salad ------ ( Hetero)
Blood ( Homo)
Ink
( Homo )
Oil/vinegar salad dressing--- (Hetero)
All of the following are pure
substances. List an ( E ) next
to the elements and a ( C )
next to the compounds.
A)
B)
Sulfur
Water
C) table salt
D) Copper
Draw the periodic table and
show where the metals,
nonmetals and metalloids are
located.
List the following in order
of particle size from
smallest to largest
particles.
- Colloids
- Solutions
- Suspensions
-
Solutions 
Colloids
 Suspensions
Solutions have particles so small and evenly
distributed that they may be mistaken as a pure
substance.
Colloids often have particles permanently
suspended within them. It may be necessary to
shine a light through them to see the particles
“ The Tyndall Effect”
Suspensions have particles so large that agitation/
movement is required to keep them in the
solution. If allowed to sit without movement
the particles will settle out of the solution.
List the following elements as a
metal (M), nonmetal (NM) or
a metalloid (ML).
a)
b)
c)
d)
Calcium
Nitrogen
Sodium
Antimony
e) silicon
f) potassium
g) chlorine
h) oxygen
a)
b)
c)
d)
Calcium (M)
Nitrogen (N)
Sodium (M)
Antimony (ML)
e) silicon (ML)
f) potassium (M)
g) chlorine (N)
h) oxygen (N)
Give 3 examples of
endothermic phase changes.
Melting ( solid  liquid )
Vaporization ( liquid  gas )
Sublimation ( solid  gas )
(dry ice (Frozen CO2)  gas)
Give 3 examples of
exothermic phase changes.
Condensation ( gas  liquid )
Freezing ( liquid  solid)
Deposition ( gas  soild)
List a “D” next to the situations
that will slow down the
evaporation of water and an “I” next
to the situations that will increase
the evaporation of water.
a)
b)
c)
d)
High temperatures
Low humidity
Pressure increase
Wind
a)
b)
c)
d)
High temperatures ( I )
Low humidity ( I )
Pressure increase ( D )
Wind ( I )
List the component parts
involved in the formation of
a homogeneous solution.
Solute- the part of the solution that
dissolves (the part added to the
other (solvent) and appears to go
away).
Solvent- the part of the solution
that does the dissolving.
List the factors that increase
the rate at which a solution
forms.
-
-
Increase the temperature of the
solvent (works with liquid or solid
solutes only)
Agitation/ shaking/ stirring
Increase in surface area (This is
generally achieved by making the
size of the solute particles smaller).
Explain the attraction
between particles of solutes
and solvents in determining
the solubility of a substance.
If the particles of a solute have
a greater attraction for each
other than the solvent particle
attraction for the solute, then the
substance will not dissolve and
will be insoluble.
If the solvent particles have a
greater attraction for the solute
particles than the solute
particles have toward each
other the solute particles will be
stripped away easily from the
other solute particles and the
substance will dissolve.
Explain why water is considered
the universal solvent.
Water is a polar molecule .
This means that it has a partial
charge. ( One end positive and the
other end is negative (poles are
created)).
The partial charge is created due to
the difference in electronegativity of
the hydrogen and oxygen atoms.
Explain what electronegativity
is and how the
electronegativity relates to
the element’s placement on
the periodic table.
Electronegativity refers to the
ability of an element to
attract electrons to it.
Electronegativity is influenced
by the electron configuration
of the atom.
What refers to the amount
of solute that will result in
100 g of water at a given
condition?
Solubility
Explain how solubility curves
of solid, liquids and gas
solutes appear as the
temperature increases.
What type of solution will
more solute dissolve in if
added to the solution at the
current conditions?
Unsaturated solution
Follow-Up Question:
How would this appear on a
solubility curve?
What would occur if a
saturated solution were
heated?
Although it currently has all the
solute that can be dissolved
within its solution heating the
solution will cause the
particles to move faster
(increases the kinetic energy )
and more solute can now be
dissolved.
What occurs when a
supersaturated or saturated
solution is allowed to cool?
Solute will precipitate out of the
solution.
What is a dilute or a
concentrated solution?
A dilute solution is a solution
in which there is a little
amount of solute present.
A concentrated solution is a
solution is one in which there
is a large amount of solute
present.
What is the equation for
density?
D=m
v
What are the units of density?
What are the tools used to
determine the mass and the
volume of objects?
List a “P” next to the physical
properties and a “C” next to the
chemical properties.
state of matter
conductivity
Density
melting point
flammability
boiling point
malleability
Luster
ductility
reactivity
color
state of matter - P
P
Density -P
melting point -P
-C
boiling point -P
P
conductivityductility - P
flammability
malleability-
Reactivity refers to the
willingness / desire of an
element to bond with other
elements. They do this in
order to be more stable by
filling their outermost energy
level. (Generally this means
they follow the octet rule).
Explain reactivity trends of the
periodic table.
Reactivity increases in metals as
you move down a column
(within a family).
Reactivity increases in nonmetals
as you move up a column
(within a family).
As you move from left  right
across a period metals will
decrease in their reactivity.
As you move from left  right
across a period nonmetals will
increase in their reactivity.
http://www.nelsonthornes.com/secondary/science/scinet/scinet/reaction/re
act/periodic.htm
What are the subatomic
particles?
How do these particles
compare in mass and charge?
Where are these subatomic
particles located?
http://carbonmolecule.wordpress.com/
How do you determine the
proton, neutron, and
electron number of atoms
and ions given a model of
an atom or its location on
the periodic table?
Protons are found in the nucleus and carry a positive
charge.
Neutrons are found in the nucleus and are electrically
neutral ( no charge ).
Electrons are located in energy levels outside the nucleus
When atoms have either
gained or lost electrons
they disrupt their
electric neutral state
and carry a charge.
They are now referred to
as a(n) _________.
-ions
Metals (which do not have many
valence electrons will have a
tendency to lose them) will form
positively charged ions (cation)
Nonmetals (which have more full
outer energy shells, will have a
tendency to gain electrons) will
form negatively charged ions
(anions)
How do you determine the
number of valence electrons
of an element?
Determine the number of
electrons of the element by
reviewing the atomic
number.
Electrically neutral atoms
have the same protons (+)
charge (atomic #) as
electrons (-) charge particles.
Use that number and the sequence above to determine
which orbitals the electrons will fill which will tell you
how many electrons are found in the outermost energy
level (valence electrons) which are the ones that are lost
or gained to form ions.
Determine the group # (family) to
which the element belongs.
Hint: You will not want to apply this rule to the transition metals because they lose
electrons from different energy levels
The group/family # will let you know
the number of valence electrons.
Keep in mind that for the groups past
the transition metals (Groups 13-18)
you will need to drop 10 making
them Groups 3-8.
How are valence electrons
used to determine oxidation
numbers?
Oxidation refers to the number of valence electrons lost or
gained during bond formation (- generally it usually
refers to the lost electrons only) .
General rule of thumb:
The valence electron number for the element will
determine if the electrons will be lost or gained.
Elements with small valence electrons numbers (Alkali
metals (group 1), Alkali-Earth metals (group 2), and
group 13 will all lose valence electrons because they
have 1-3 valence electrons in their outermost energy
level.
The nonmetals (specifically groups 15-17) will gain
electrons because they have 5-7 valence electrons
already and need only to gain 1-3 more to have a full
outermost energy level (octet rule)
Oxidation number is associated with the valence electrons
lost or gained in order to create a full outermost energy
level.
Group Number
valence
electron #
Electrons
lost/ gained
Oxidation
Number
Alkali Metals Group 1
1
1- lost
1+
Alkali-Earth Metals
Group 2
2
2- lost
2+
Group 3 (really 13)
we skipped the transition metals
3
3- lost
3+
Group 4 (really 14)
we skipped the transition metals
4
4- can be lost 4+ /4or gained
Group 5 (really 15)
We skipped the transition metals
5
3- gained
3-
Group 6 (really 16)
We skipped the transition metals
6
2-gained
2-
Group 7 (really 17)- The Halogens
We skipped the transition metals
7
1-gained
1-
8
None lost
or gained
No
oxidation #
Group 8 (really 18)- The Noble Gases
We skipped the transition metals
Why are valence electrons
important?
Valance electrons are the part of the atom
that determines the chemical properties of
the atom.
Valence electrons because they are the most far
from the nucleus will have the least attraction
force acting on them and therefore are the
electrons that are involved in bonding.
What are the types of
chemical bonds and how do
the electrons behave during
the formation of these
bonds?
Covalent bonds- During this type
of bond the valence electrons
are shared in order for both to
have full outermost energy levels.
Ionic bonds- During this type of
bond the valance electrons are
transferred from the metal to the
nonmetal / polyatomic ion.
Are the valence electrons
shared equally during all
covalently bonded
compounds?
No,
Polar covalent compounds are the
covalently bonded compounds in
which valence electrons are shared
unequally due to differences in
electronegativity.
Nonpolar covalent compounds are
covalently bonded compounds in
which the valance electrons are
shared equally due to very similar
electronegativity values.
Differences = 1.7 or greater, bond is
ionic.
Between 0.5 and 1.7 the bond is polar.
Less than 0.5 = nonpolar
http://www.biog1445.org/demo/01/electronegativit
y.html
What are Lewis- Dot
structures?
How are they created and what
do they represent?
Lewis dot structures are a shorthand way used to discuss the
movement of electrons during
bonding.
You write the element symbol, then
use dots around the symbol to
show the number of valence
electrons found in an atom of that
element.
Now that you know how
elements behave during
chemical bonding, how do
you name the compounds
that are formed from the
combining of elements?
If the elements involved include a metal or a polyatomic
ion, then the compound will be ionic.
If ionic you always write the name of the metal (or
polyatomic ion if no metal is present) first. The end of
the nonmetal name generally is dropped and substituted
with –ide.
Transition metals (found in Groups 3-12) can lose electrons
from more than one energy level and therefore can have
more than one oxidation number. Because of this it is
important to identify the oxidation number of the
transition metal.
Rule of thumb:
Include the oxidation number as a Roman numeral
following the name of the metal if the metal is not found
in Group 1, Group 2 or is not Zinc (Zn), Aluminum
(Al), Cadmium (Cd), or Silver (Ag).
Ex: Fe2O3= iron (III) oxide.
Vs. NaCl= sodium chloride
Yes,
General assumption is that you take the subscript number (number that
follows the element symbol) and slide it up diagonally thus assigning the
charged oxidation number to the other element of the compound.
Ex: Ca(OH)2 = Ca (with a understood subscript of 1 would slide up and
diagonal to become the oxidation number of the polyatomic ion (OH).
Since OH is listed second in the chemical formula it stands to reason that
the oxidation # would be negative since positive elements/ polyatomic
ions are written first.
OH is a polyatomic ion and has been assigned one subscript number for the
entire ion. (OH)2. The subscript 2 would slide up and diagonally to
become the oxidation number of the metal Calcium.
We believe Ca- 2+ and OH= 1-. We can check this by our knowledge that Ca
in group 2 has 2 valence electrons that as a metal it will lose when
forming compounds and the polyatomic ion chart states that OH has a –
charge.
Yes, since all elements /polyatomic ions
combine to form neutral equations the sum
of their charges would have to equal zero.
Ex: Ca (OH)2
We can also check this using the following
formula.
The sum of the
{(Subscript #) X (oxidation #)} + {(Subscript #) X (oxidation#)} = must equal
zero.
Ex:
Ca
1(2+)
OH
+ 2(1-) = o
You would look for the subscript number and
use a prefix to state the number of atoms
from that element that are present in the
compound.
Ex: CO= carbon monoxide
CO2= carbon dioxide
Number
Prefix
1
Mono
2
Di
3
Tri
4
Tetra
5
Penta
6
Hexa
7
Hepta
8
Octa
9
Nona
10
deca
How do you know when to
use the prefixes?
You use prefixes to name compounds that have
formed by creating covalent bonds (shared their
electrons). So when 2 nonmetals are present.
You use a prefix before the element name to indicate
the number of atoms of that element that are
present in the compound.
You use a prefix before the first element’s name if the
subscript number is 2 or higher.
You use a prefix before the second element’s name for
all subscript values.
CH4
Na2 CO3
H2O
BF3
Li2S
O2
CH4 : Covalent (carbon tetrahydride)
Na2 CO3 : ionic ( sodium carbonate)
H2O : covalent ( dihydrogen monoxide)
BF3 : covalent (boron trifluoride)
Li2S : ionic (lithium sulfide)
O2 : covalent (oxygen)
Explain why you would
change the coefficient in a
chemical equation only and
never the subscript within the
chemical formula.
Changing the coefficient only
changes the quantity (amount) of
the substance itself. It does not
change what the substance is.
If you change the subscript you are
changing the substance.
__ AlBr3 + __ K2SO4  __ KBr + __
Al2(SO4)3
__ P +
__ NaCl
__ O2
 __ P2O5
+ __ F2
__ KClO3  __ KCl
 __ NaF
+ __ O2
+
__ Cl2
2 AlBr3 + 3 K2SO4  6 KBr + 1 Al2(SO4)3
4P +
2 NaCl
5 O2

+ 1 F2
2 KClO3  2 KCl
2 P2O5
 2 NaF
+ 3 O2
+
1 Cl2
__ AlBr3 + __ K2SO4  __ KBr + __ Al2(SO4)3
Aluminum bromide + potassium sulfate yields
potassium bromide + aluminum sulfate
__ P + __ O2  __ P2O5
Phosphorous + oxygen yields diphosphorous pentoxide
__ NaCl + __ F2  __ NaF + __ Cl2
Sodium chloride + fluorine yields sodium fluoride +
chlorine
__ KClO3  __ KCl + __ O2
Potassium chlorate yields
potassium chloride
+
oxygen
__ AlBr3 + __ K2SO4  __ KBr + __
Al2(SO4)3
Double displacement
__ P +
__ NaCl
__ O2  __ P2O5
Synthesis
+ __ F2  __ NaF +
Single displacement
__ KClO3  __ KCl + __ O2
Decomposition
__ Cl2
Explain why acid/ base
reactions (a type of double
displacement) is also
considered a neutralization
reaction?
Neutral= pH of 7 (like pure distilled water)
Occurs when the number of H+ ions is equal to OH- ions
such as observed in water H2O.
H2O is made up of two H and one O or
One H+ ion and one OH- ion.
In an acid / base reaction the H from the acid and the
OH from the base combine to form water.
Ex: HCl + NaOH
 NaCl + H2O
H + from the hydrochloric acid combines with the OHfrom sodium hydroxide (base) to form water.
Neutralization (Acid/Base) reactions yield the products
of salt (NaCl- metal + halogen) and water.
What is meant by pH?
pH= potential hydrogen.
The pH scale is a scale that
measures the amount of
hydronium ions in solution. This
is more abundant in acids than
bases because they release H+
ions that bond with H2O to form
hydronium (H3O+) ions.
What is the range of the pH
scale where do acids and
bases belong on this scale?
I---------------------------------------------------I
0
7
14
Acids= 0 – 6.9
Bases = 7.1 – 14
Strong Acids toward 0
Strong Bases toward 14
Weak acids around 6 (closer to 7)
What are the characteristics
of acids?
What are the characteristics of
bases?
Acids:
Release H+ ions in
solution that combine
with water to form
hydronium ions.
Strong acids completely
ionize in solution.
Taste sour
Turns blue litmus paper
red
All acids will conduct
electricity in water.
Known as proton
donors
Bases:
Release OH- ions or form
OH- ions in solution.
Bases will dissociate in
solution.
Taste bitter
Turns red litmus paper
blue
Bases feel slippery
Are used in cleaning
Are referred to as alkali
Known as proton
acceptors
NaHCO3 - sodium bicarbonate (baking soda)
CH3COOH- found in small dilute amounts in
household vinegar.
Ca(OH)2- calcium hydroxide
HCl- found in the human stomach
NaHCO3 - base
Ca(OH)2- base
CH3COOH- acetic acid
HCl- hydrochloric acid
Acids/ Bases defined by Arrhenius theory:
Acids- produce hydrogen ions
Bases- produce hydroxide ions.
Acids/Bases defined by Bronsted-Lowry theory:
Acids- are proton donors
Bases- are proton acceptors
What would be found as a
reactant of a combustion
reaction?
Oxygen
CH4
+ O2
 CO2
+ H2O
In combustion reactions oxygen is
one of the reactants because things
will not burn without oxygen
present.
Hydrocarbon + oxygen recombine to
form carbon dioxide (or sometimes
CO) and water.
How do alpha particle and
beta particle radiation
compare?
What is an expected product
of each type of radiation?
To what degree will this type
of radiation penetrate
Nuclear radiation /
decay
Alpha particle
decay
What you should see as a
product of this type of
radiation.
4
How damaging is
this type of decay?
He
- Because the alpha
particle is so large
-Occurs as a large
it can barely pass
particle containing 2
the other product resulting
through a sheet of
protons and 2
from alpha particle radiation
paper. They lose
neutrons is ejected
would have a mass # four less and energy rapidly as
from the nucleus
an atomic # two less than the
they ionize matter.
(A Helium atom)
original atom that underwent
alpha particle decay.
Beta particle decay
2
_______________________
o
e
-1
- Occurs as a
____________________________
neutron decays into The other product of beta particle
a proton and an
decay would have the same mass
electron. The
number, but would have an atomic
electron is ejected
# one more than the original atom
from the nucleus.
that has undergone beta particle
-Because they are
smaller in mass they
interact with the
material they pass
through less than do
alpha particles and
can penetrate a few
millimeters of
Explain why you need lead or concrete to stop
the radiation emitted by gamma radiation?
Why does the mass and atomic number of the
product of gamma radiation appear the same
as the original substance before the radiation
occurred?
Gamma radiation is actually high energy
waves that are poor at ionizing material as
they pass through it, so it loses little to no
energy as it moves through an object.
You would expect the mass of the product to
be the same as the original mass because
gamma radiation deals with energy not
mass.
Nuclear Fusion
-
-
Occurs when lighter
nuclei combine to form
heavier nuclei
This is the process that
star radiation occurs.
Nuclear Fission
-This occurs when heavier
nuclei breakdown into
lighter nuclei
-This is the way in which
nuclear power plants
provide energy and also
how the Earth heats
itself from the inside
out.
What are isotopes and why are
they important?
Isotopes are atoms of the same
element that have the same
number of protons, but different
number of neutrons.
The different number of neutrons
make the nucleus unstable and it
begins to decay.
Isotopes are important because
they release energy and can also
be used to determine the age of
carbon based organisms.
(Carbon dating).
What is meant by half –life?
- The amount of time it takes for
half of the original sample to
decay.
The following is a website where you
can practice completing half-life
problems.
http://www.mdc.edu/kendall/chmphy/nuclear/halflive.
htm
Some substances have the ability to absorb and
retain more heat than do other substances.
The link below will take you to a website on heat
capacity use it to determine how substances
heat and retain their absorbed heat differently.
There are also problems that you can work out on
heat capacity.
http://wps.prenhall.com/wps/media/objects/46
78/4790699/ch08_08.htm
How do thermal energy, heat
and temperature compare?
Thermal energy- is the kinetic energy of the
movement of atoms, molecules and electrons.
Heat-the form of thermal energy transferred
between the atoms, molecules that are in
motion.
Temperature- the measurement of the amount of
thermal energy within a substance.
What is latent heat?
What is the relationship of
latent heat and phase change?
Latent heat is the energy released or absorbed by an
object during a process in which the temperature stays
the same.
During a change in phase (such as melting/vaporization,
or condensation/freezing the temperature remains
constant. The temperature does not change during a
phase change because once the amount of kinetic
energy (temperature) has been reached the reaction
(bonds forming/breaking) continues until the
molecules have all undergone the process .
Latent heat would be absorbed from the surroundings to
the object in endothermic reactions such as (melting
and vaporization) and would be released to the
surroundings from the object in exothermic reactions
such as condensation and freezing.
Can you identify the parts of
a phase change diagram?
Note that the particles are closer together in a solid than they are in a liquid
or gas.
The potential energy changes as energy is absorbed or released which lead to
changes in the kinetic energy. However during the time the substance is
What roles do potential and
kinetic energy play during
a phase change?
Potential energy – refers to the energy stored within the
substance. This stored energy is found between the
molecules that make up the substance. As energy
fluctuates in a system the potential energy changes.
The kinetic energy stays the same if the temperature
remains constant (such as it does during a phase
change).
If the kinetic energy does not change (thus the temperature
does not change) then why does the phase of matter
change?
-the change in the phase of matter is due to the
increase/decrease in the potential energy (space
between the atoms ).
What role does height and
gravity play on potential and
kinetic energy?
PE= mgh
(potential energy= mass X gravitational acceleration X
height)
KE = ½ mv2
squared)
(Kinetic energy = ½ mass X velocity
Compare the 3 forms of heat
energy transfer:
Conduction, Convection &
radiation
Conduction- transfers heat energy from an area of
higher heat concentration to an area of lesser
heat concentration between two objects that are
touching.
Ex: Heat is transferred from hot coffee to the cup
(which has less heat) to your hands.
Ex: Heat is transferred from your hand (which has
more heat) to an ice cube (which has less heat)
and the ice cube melts. Your hand feels cold
because some of the heat was removed from
your hand, not because the ice cube released the
cold to your hand.
Convection - is the transfer of heat energy due to
differences in the density of the substances involved.
Warmer (less dense) substances are less dense because
the atoms that form them are further away from one
another, or there are fewer of them. Less dense
materials tend to flow above more dense objects.
This property of matter where less dense material will
move over more dense material generates movement.
Ex: Mantle convection (mechanism for the plate tectonic
theory you learned about in Earth Science).
Ex: Why the air in a room is cooler toward the floor than
it is toward the ceiling.
Radiation- is the movement of heat energy from a
central core region outward in all directions.
Radiation (especially heat radiation from the sun)
will travel as electromagnetic waves. As
electromagnetic waves it will not require a
medium through which to travel.
How does friction change
mechanical energy into heat?
The moving parts of mechanical energy rub
against each other. This interaction between
the parts will generate friction. The friction of
the parts interacting with each other will
generate friction.
The friction of the moving parts will convert
mechanical energy into heat.
What is the definition of work
and what formula is used to
calculate if work has been
done?
Energy transferred over a distance.
The formula is just how it sounds.
Energy is needed to move an object over a
distance.
W= F x d
Work= force x distance
In what types of scenarios
would no work be done?
In cases where objects do not move from their
current position and do not travel over a
distance at the instance in which the question is
being asked.
What is the relationship
between work and power?
Power is the rate at which work is done.
Power is defined by the equation
P=W
Remember: W = F x d
t
Remember that you do not have to have the work
and the time. You can be given the force, distance
and time and find the power involved.
What are the units that measure:
Work
Energy
Power
Force
Distance
Time
Work----- Joules ( J )
Energy--- Joules ( J )
Power---- Watts ( W )
Force----- Newton ( N )
Distance—Meters ( m )
Time----- seconds ( s )
Wheel and axle
Screw
Inclined plane
Wedge
Lever
Pulley
Wheel & axle, pulley, lever,
inclined plane, screw, wedge
Compound Machines:
1- Scissors
2- Car Jack
3- Wheelbarrow
4- Axe
Scissors=
Car Jack=
lever, wedge and a screw
handle (lever) + screw (inclined plane)
Wheelbarrow =
Axe =
levers + wheel & axle
wedge, lever
Input force= the force you apply to the
object / machine.
Output force= the force that is applied to the
object you wish to move or the task you
want to do.
Mechanical Advantage refers to taking a small
input force and magnifying the output force.
Sometimes machines will increase the distance, not the force.
When this occurs the same force is used, but it is applied
over a greater distance. This is like what a ramp does.
It is easier to move an object for a longer distance at a
smaller applied force than for a shorter distance that
requires a much harder force.
To determine the Mechanical Advantage when distance
has been increased the equation is the same format as the
above where output distance is divided by input distance.
http://www.racemath.info/graphics/graphs/graph_vel.gif
http://www.physicsclassroom.com/class/momentum/u4l1a.cfm
http://www.physicsclassroom.com/class/newtlaws/u2l4a.cfm
http://www.safetyoffice.uwaterloo.ca/hse/radiation/rad_sealed/matter/gr
aphic/atom.jpg
http://www.classzone.com/books/earth_science/terc/content/investigatio
ns/es0501/images/es0501_p6_readinginfo_b.gif
http://images.tutorvista.com/cms/images/83/electronicconfiguration1.PNG
http://chemsite.lsrhs.net/ChemicalBonds/electronegativity.html
http://www.files.chem.vt.edu/RVGS/ACT/notes/electronegativity.html
misterguch.brinkster.net/HM009.doc
http://www.chemguide.co.uk/physical/acidbaseeqia/theories.html
http://www.passmyexams.co.uk/GCSE/physics/penetrating-properties-ofradiation.html
http://chemistry11mrstandring.wikispaces.com/Phase+Changes-by+AnnYU
http://innovationcharter.pbworks.com/w/page/19966640/Data%20fro
m%20Experiments-%20Michael%20Faraday