S8 EXAM REVIEW
Physical Science
Physical Science is mainly the study of
MATTER & ENERGY
The two main branches of physical science are CHEMISTRY & PHYSICS
Chemistry is the study of the interactions of MATTER ( “stuff”)Physics is the study of forms of ENERGY
What are the three types of scientific models?
PHYSICAL CONCEPTUAL MATHEMETICAL
GIVE AN EXAMPLE OF A CONCEPTUAL MODEL
THE ‘BIG BANG” THEORY
Experiments are designed to testHYPOTHESES
THEORY vs LAW
THEORY EXPLAINS
Scientific theory is an explanation for phenomenon based on observation and experimental results.
LAW STATES
Scientific LAW is a statement or summary of many experimental results and observations.
The tendency of an object to resist a change in motion INERTIA
The amount of space an object takes up VOLUME
A property of matter ( a measurement) that is affected by the gravitational force acting on it WEIGHT
Particles in this state are far apart and move independently of each other
The absolute best way to tell that a chemical change has taken place is that
According to Charles’s Law, a balloon
NEW SUBSTANCE with NEW PROPERTIES is formed
GAS
DECREASES in VOLUME when the
TEMPERATURE DECREASES(stick figure of Charles showing goofy arms and legs with TV on them)
How do elements form compounds?
in a SPECIFIC MASS RATIOthat are shown by subscripts in a chemical formula
A pure substance made of two or more elements that are chemically combined
COMPOUNDThe smallest particle into which an element can be divided and is still the same substance is
ATOM
The equation for Newton’s Second Law is
F = m x aExamples of projectile motion always contain the expression of an object _______ the surface of the earth and an invisible __________ path as it ________ to earth.
LEAVING CURVED RETURNSIf sugar is dissolved in water, the water is known as the ____ and the sugar is called the SOLUTE. SOLVENT
Democritus, Dalton, Thomson, Rutherford and Bohr all____ to the ___ of the ____ ____.
CONTRIBUTED DEVELOPMENT ATOMIC THEORY
Ernest Rutherford discovered the existence ( in the center of an atom) of a
PROTON
ISOTOPES always have the SAME number of ____ but different numbers of ___.
same # PROTONS different # NEUTRONS
A good description of the nan ucleus ( which contains almost all the mass of an atom)
DENSE & POSITIVELY CHARGED
The subatomic particle with the LEAST amount of MASS( almost massless)
ELECTRONThe most likely location of electron is in the ___ ___ according to modern atomic theory.
ELECTRON CLOUD
RULES FOR COUNTING ATOMS
1. SUBSCRIPTS only refer to the atom that they are BEHIND. For example…
H2SThere are TWO atoms of HYDROGEN and only ONE atom of SULFUR.
COEFFICIENTS
2. COEFFICIENTS apply to the entire compound. You MULTIPLY the coefficients and SUBSCRIPTS.
2 H2S
ATOMS OF HYDROGEN:
ATOMS OF SULFUR:
4
2
IF THERE ISN’T A SUBSCRIPT BEHIND AN ELEMENT, ASSUME THERE IS ONLY ONE ATOM OF THAT ELEMENT!
PARENTHESES
3. If elements or compounds are inside of PARENTHESES, then the SUBSCRIPT behind the parentheses applies to everything inside.
Ba(OH)2
ATOMS OF BARIUM:
ATOMS OF OXYGEN:
ATOMS OF HYDROGEN:
1
2
2
LET’S PRACTICE!
MgCl2
Atoms of Magnesium:
Atoms of Chlorine:
1
2
Al2S3
Atoms of Aluminum:
Atoms of Sulfur:
23
What about this BAD BOY???
2Ca3(PO4)2 Atoms of Calcium:Atoms of Phosphorus:Atoms of Oxygen:
64
16
Balancing Chemical Equations
List elements. Count atoms on reactant and product
sides.Adjust COEFFICIENTS ONLY to obtain
equal amounts of atoms.
First you need an equation with the correct “formulae” ………. You’ll probably be given this in the question
Just like this one
Mg + O2 MgO
Then all you do is list the atoms that are involved on each side of the arrow
Mg + O2 MgOMgO
MgO
[1] Just count up the atoms on each side
Then start balancing:
Mg + O2 MgOMg
O
1
1
1
2
[2] The numbers aren’t balanced so then add “BIG” numbers to make up for any shortages
And adjust totals
Mg + O2 MgOMg
O
1
1
1
2
2
2
2
Mg + O2 MgOMg
O
1
2
2
2
2
But the numbers still aren’t equal, so add another “BIG” number
2
And adjust totals again
NOW BOTH SIDES HAVE EQUAL NUMBERS OF ATOMS
WE SAY THAT THE EQUATION IS BALANCED!!
2
Try to balance these equations using the same method:
[1] Na + Cl2 NaCl
[2] CH4 + O2 CO2 + H2O
[4] Al + O2 Al2O3
[3] Li + HNO3 LiNO3 + H2
How did you get on??
[1] 2 Na + Cl2 2 NaCl
[2] CH4 + 2 O2 CO2 + 2 H2O
[4] 4 Al + 3 O2 2 Al2O3
[3] 2 Li + 2 HNO3 2 LiNO3 + H2
Here are the answers:
HOPE YOU’VE GOT THE IDEA… REMEMBER TO CHECK THAT YOU CAN DO ELECTROLYSIS
EQUATIONS TOO
For a chemical bond to break
ENERGY IS REQUIRED
If a chemical symbol in a chemical formula has no subscript, it means that
Only ONE ATOM of the element is in the MOLECULE
Periodic mean happening at ____ ____.
REGULAR INTERVALS
Periodic Law states that ___ of elements change ___ with the element’s __ __.
PROPERTIES PERIODICALLY ATOMIC #s
Each VERTICAL column on the periodic table is called a(n)
GROUP FAMILY
Each HORIZONTAL row on the periodic table
PERIOD SERIES
Most of the elements on the PT are
The elements to the right of the zigzag line are
Mendeleev grouped the elements according to
METALS
NONMETALS
INCREASING ATOMIC MASSHenry Moseley changed the arrangement to atomic number - the way it is today.
Physical and chemical properties of elements change
ACROSS EACH PERIOD
The substance necessary for substances to burn
OXYGENThis is PROOF that a chemical reaction has taken place NEW substance with
NEW PROPERTIES formed
Waves TRANSFERENERGY ONLY
This type of wave requires a MEDIUM (some type of matter) SOUND WAVE
This type of wave does NOT require a medium and can thus travel in outer space
RADIO WAVE
THE RATIO OF MATTER IN A GIVEN VOLUME
DENSITY
amount of space an object occupies – a measure of size VOLUME
amount of matter in an object MASS
How hot or cold something is, usually measured in degrees Celsius or Kelvin
TEMPERATURE
The change of state from liquid to gasEVAPORATION
A liquid’s resistance to flowVISCOSITY
A change in which energy is added to a substance
ENDOTHERMIC
A change in state directly from a solid to gas
SUBLIMATIONElement that has properties of metal and
nonmetal METALLOID
Element that conducts heat and electricity poorly and can be a solid, liquid, or gas
NONMETAL
A pure substance that cannot be separated into simpler substances by physical or chemical means
ELEMENTAn element that is shiny and conducts heat and
electric currentMETAL
A sample of matter, either a single element or a single compound, that has definite physical and chemical properties
PURE SUBSTANCE
An object at test stays at rest and an object in motion stays in motion unless acted on by a force that changes it
Newton’s 1st Law
Acceleration is caused by a force acting on massNEWTON’S 2ND LAW
For a force on an object, there is an equal and opposite force that exists
NEWTON’S 3RD LAW
The force that opposes the motion of objects through air
AIR RESISTANCE
An unbalanced force that causes objects to move in a circular path
CENTRIPETAL FORCE
The motion of a body when free fall acts on itFREE FALL
The path of one object around another in spaceORBIT
The curved path of a thrown object near the earth’s surface
PROJECTILE MOTION
The constant velocity of a falling object when the force of gravity is balanced by air resistance
TERMINAL VELOCITYA negatively charged particle
ELECTRON
Positively charged particle PROTON
Un charged particle NEUTRON
Number of protons in the nucleus ATOMIC NUMBER
Mass of an atom expressed in atomic mass units- a weighted average
ATOMIC MASS
Sum of protons and neutronsMASS NUMBER
Describes the mass of an atomATOMIC MASS UNIT
The larger number on any element key of any element on the PT
ATOMIC MASS
The smaller whole number on any element key on PT
ATOMIC NUMBER
The parts of a chemical equation that are on the left side- original substances
REACTANTSThe part(s) of a chemical equation on the right
side- things formedPRODUCTS
Small numbers below that indicate number of atoms of element in formula
SUBSCRIPTLarge numbers in front of chemical formulas
COEFFICIENT
Distance traveled plotted graphed over time travelled shows
AVERAGE SPEED
Velocity graphed over time traveled (with upward slope) shows
POSITIVE ACCELERATION