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Title: Science Framework for California Public School


1
Science Framework for California Public School
  • Mr. Gowers
  • Chemistry

2
Standard 1Atomic and Molecular Structure
  • 1.The periodic table displays the elements in
    increasing atomic number and shows how
    periodicity of the physical and chemical
    properties of the elements relates to atomic
    structure.

3
Standard 1
  • a. Students know how to relate the position of
    an element in the periodic table to its atomic
    number and atomic mass.
  • The number of protons, not electrons or neutrons,
    determines the atomic number.
  • Elements are arranged on the periodic table in
    order of increasing atomic mass.
  • Isotopes differences in the number of neutrons
    of the same element.

Atomic number (Z) number of protons in nucleus
Mass number (A) number of protons number of
neutrons
atomic number (Z) number of neutrons
4
Hydrogen
Deuterium
Tritium
5
Do You Understand Isotopes?
How many protons, neutrons, and electrons?
6 protons, 8 (14 - 6) neutrons, 6 electrons
How many protons, neutrons, and electrons are in?
6 protons, 5 (11 - 6) neutrons, 6 electrons
6
Standard 1
  1. Students know how to use the periodic table to
    identify alkali metals, alkaline earth metals and
    transition metals, trends in ionization energy,
    electronegativity, and the relative size of ions
    and atoms.

7
  1. Alkali metals Group 1(ie. Na K) Soft white
    and extremely reactive.
  2. Alkaline earth metals Group 2 (ie. Mg Ca).
  3. Transition Metals Groups 3 12 (Common metals
    like iron gold) Have electrons in the d
    orbitals.
  4. Electronegativity a measure of the ability of an
    atom of an element to attract electrons toward
    itself in a chemical bond (0 4).
  5. Ionization energy energy it takes to remove an
    electron from the atom.
  6. Both Electronegativity and Ionization energy
    increase from bottom to top and left to right.
  7. Atomic ionic sizes increase from top to bottom
    and right to left. (Exception with full or ½ full
    subshells)
  8. Cations are smaller than their neutral form and
    Anions are larger than their neutral state.

8
Students know how to use the periodic table to
identify metals, semimetals, nonmetals, and
halogens.
9
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12
Standard 1
  • Students know how to use the periodic table to
    determine the number of electrons available for
    bonding.
  • Valence electrons.
  • Valence electrons are equal to the Group number
    (ie. Group 1 has 1 valence electron).
  • Useful in determining how many electrons are
    involved in bonding (ie. MgCl2).
  • e. Students know the nucleus of the atom is much
    smaller than the atom yet very dense (contains
    most of its mass).

13
Standard 2
  • Students know atoms combine to form molecules by
    sharing electrons to form covalent or metallic
    bonds or by exchanging electrons to form ionic
    bonds.
  • Covalent shared electrons electrons overlap
    between the two atomic orbitals.
  • Metals valence electrons are not localized
    (delocalized) allowing them to move between
    orbitals of adjacent metals (conduct
    electricity).
  • Ionic transfer of electrons.
  • Polar covalent unevenly shared electrons.
  • Octet Rule

14
Valence electrons are the outer shell electrons
of an atom. The valence electrons are the
electrons that participate in chemical bonding.
15
The Ionic Bond
He
Ne
1s22s1
1s22s22p5
1s2
1s22s22p6
16
A covalent bond is a chemical bond in which two
or more electrons are shared by two atoms.
Lewis structure of F2
17
Lewis structure of water


Double bond two atoms share two pairs of
electrons
or
Triple bond two atoms share three pairs of
electrons
or
18
Lengths of Covalent Bonds
Bond Type Bond Length (pm)
C-C 154
C?C 133
C?C 120
C-N 143
C?N 138
C?N 116
Bond Lengths Triple bond lt Double Bond lt Single
Bond
Bond Strength Triple bond gt Double Bond gt Single
Bond
19
Polar covalent bond or polar bond is a covalent
bond with greater electron density around one of
the two atoms
electron rich region
electron poor region
e- rich
e- poor
d
d-
20
Classification of bonds by difference in
electronegativity
Difference
Bond Type
0
Covalent
? 2.0
Ionic
0 lt and lt2.0
Polar Covalent
21
Cs 0.7
Cl 3.0
3.0 0.7 2.3
Ionic
H 2.1
S 2.5
2.5 2.1 0.4
Polar Covalent
N 3.0
N 3.0
3.0 3.0 0
Covalent
22
Standard 2
  • Students know chemical bonds between atoms in
    molecules such as H2, CH4, NH3, H2CCH2, N2, Cl2,
    and many large biological molecules are covalent.
  • Organic biological molecules consist primarily
    of carbon, oxygen, hydrogen, nitrogen. These
    elements share valence electrons to form bonds so
    that they have electron configurations like their
    nearest noble gas. (Octet Rule)
  • Noble gases inert gases (column 18).

23
Standard 2
  • Students know salt crystals (NaCl) are repeating
    patterns of positive and negative ions held
    together by electrostatic attraction.
  • Lattice energy the energy that holds ionic
    compounds together.
  • Cations positive charge.
  • Anions negative charge.

24
Standard 2
  • Students know the atoms and molecules in liquids
    move in a random pattern relative to one another
    b/c the intermolecular forces are too weak to
    hold the atoms or molecules in a solid form.
  • When enough energy is added to the solid, the
    kinetic energy of the atoms molecules increases
    sufficiently to overcome the attractive forces
    between the particles, they break (melting
    point) which forms a liquid (disorder). The
    particles in the liquid are free to move although
    they remain in contact w/ each other.

25
Standard 2
  • Students know how to draw Lewis dot structures.
  • 1) Lewis dot structures show how valence
    electrons and covalent bonds are arranged between
    atoms in a molecule.

26
VI. Lewis Structures Representation of
_________ bonding in molecules.
covalent
Group e- dot of bonds lone pairs
1
2
13
14
15
16
17
18

x
1
0

x

2
0


x
3
0




x
4
0



x
3
1






x
2
2






x
1
3








x
0
4




27
Writing Lewis Structures
Technique 1. Find the total number of _______
electrons in the molecule. 2. Add __ for each __
charge subtract __ for each __ charge. 3. Write
skeleton structure with _____ bonds (generally
the element which makes the greatest number of
bonds will be the ______ atom). 4. Place
remaining valence electrons around the ____
elements until octets are filled. 5. Place
valence electrons around the ______ atom until
octet is formed. 6. If you run out of electrons
(look at the total you calculated), then ______
or ______ bonds will be formed. 7. The goal is
to draw a structure that uses the correct number
of ________ which has an ____ around each
atom. 8. Hydrogen is an ________ to the octet
rule. It can only form _ bond and have a total
of _ electrons (to become like ______). 9.
Elements will be most _____ if they contain the
number of bonds and the number of lone pairs as
shown in the above table.
valence
1
1

single
central
outer
central
double
triple
electrons
octet
exception
1
2
helium
stable
28
Step 1 N is less electronegative than F, put N
in center
Step 2 Count valence electrons N - 5 (2s22p3)
and F - 7 (2s22p5)
5 (3 x 7) 26 valence electrons total
electrons in your budget
Step 3 Draw single bonds between N and F atoms
and complete octets on N and F
atoms.
Step 4 - Check. Did you spend your budget? In
other wards are of e- (electrons) in structure
equal to number of total of valence e- ?
3 single bonds (3x2) 10 lone pairs (10x2) 26
valence electrons
29
Standard 3
  • Students know how to describe chemical reactions
    by writing balanced equations.
  • Nomenclature.
  • Tips for balancing equations
  • a) Number of atoms of products must equal number
    of atoms of reactants.
  • b) Coefficients are whole numbers written at the
    front of the substances.

30
Standard 3
  • c) All atoms are balanced by the coefficients.
  • d) Subscripts are NOT changed.
  • e) Keep polyatomic ions together as a unit if not
    changed from reactants to products.
  • f) Balance single elements last.
  • g) Use the even/odd rule.
  • h) If an element is in multiple compounds,
    balance that element last.

31
Chemical Nomenclature
  • Ionic Compounds
  • often a metal nonmetal
  • anion (nonmetal), add ide to element name

BaCl2
barium chloride
K2O
potassium oxide
Mg(OH)2
magnesium hydroxide
KNO3
potassium nitrate
32
  • Transition metal ionic compounds
  • indicate charge on metal with Roman numerals

iron(II) chloride
FeCl2
2 Cl- -2 so Fe is 2
FeCl3
3 Cl- -3 so Fe is 3
iron(III) chloride
Cr2S3
3 S-2 -6 so Cr is 3 (6/2)
chromium(III) sulfide
33
Molecular Compounds
HI
hydrogen iodide
NF3
nitrogen trifluoride
SO2
sulfur dioxide
N2Cl4
dinitrogen tetrachloride
NO2
nitrogen dioxide
N2O
dinitrogen monoxide
34
Balancing Chemical Equations
  1. Write the correct formula(s) for the reactants on
    the left side and the correct formula(s) for the
    product(s) on the right side of the equation.

Ethane reacts with oxygen to form carbon dioxide
and water
  1. Change the numbers in front of the formulas
    (coefficients) to make the number of atoms of
    each element the same on both sides of the
    equation. Do not change the subscripts.

35
Balancing Chemical Equations
  1. Start by balancing those elements that appear in
    only one reactant and one product.

start with C or H but not O
multiply CO2 by 2
multiply H2O by 3
36
Balancing Chemical Equations
  1. Balance those elements that appear in two or more
    reactants or products. (Double your odds)

37
Balancing Chemical Equations
  1. Check to make sure that you have the same number
    of each type of atom on both sides of the
    equation.

38
Standard 3
  • Students know the quantity one mole is set by
    defining one mole of carbon-12 atoms to have a
    mass of exactly 12 grams.
  • Mole the number of atoms in 12 grams of pure
    carbon-12.
  • Students know one mole equals 6.022 x 1023
    particles (atoms or molecules) (Avogadros
    number).

39
Standard 3
  • d. Students know how to determine the molar
    mass of a molecule from its chemical formula and
    a table of atomic masses and how to convert the
    mass of a molecular substance to moles, number of
    particles, or volume of gas at standard
    temperature and pressure. Road Map!!!!
  • e. Students know how to calculate the masses
    of reactants and products in a chemical reaction
    from the mass of one of the reactants or
    products. Road Map!!!!

40
C. Road Map (Memorize)
  • A B ? C D

Mass (g) A
Mass (g) D
Mol to mol ratio!!!
Particles A Molecules A Atoms A
Particles D Molecules D Atoms D
6.022 x 1023
6.022 x 1023
Moles D
Moles A
Coefficients From Balanced
22.4 L
22.4 L
Chemical Equations
Volume of gas D
Volume of gas A
Coefficients
(Same T P)
41
How many H atoms are in 72.5 g of C3H8O ?
1 mol C3H8O (3 x 12) (8 x 1) 16 60 g C3H8O
1 mol C3H8O molecules 8 mol H atoms
1 mol H 6.022 x 1023 atoms H
72.5 g C3H8O
5.82 x 1024 atoms H
42
Methanol burns in air according to the equation
If 209 g of methanol are used up in the
combustion, what mass of water is produced?
molar mass CH3OH
molar mass H2O
coefficients chemical equation
209 g CH3OH
235 g H2O
43
Theoretical Yield is the amount of product that
would result if all the limiting reagent reacted.
Actual Yield is the amount of product actually
obtained from a reaction.
44
Standard 4 Gases and Their Properties
  • The kinetic molecular theory describes the motion
    of atoms and molecules and explains the
    properties of gases.
  • Students know the random motion of molecules and
    their collisions with a surface create the
    observable pressure on that surface.
  • Fluids consist of molecules that freely move, but
    intermolecular forces hold the atoms or molecules
    close to each other.

45
Standard 4 Gases and Their Properties
  • 2) Gases consist of tiny particles (atoms or
    molecules) spaced far apart from each other and
    move freely at high speeds, near the speed of
    sound.
  • 3) Pressure a force per unit area.
  • 4) Pressure is caused by the collisions of atoms
    or molecules with the walls of the container.
  • 5) Pressure in water increases with depth, and
    pressure in air decreases with altitude.

46
Standard 4
  • Students know the random motion of molecules
    explains the diffusion of gases.
  • Heavier gases have a slower rate of diffusion.
  • Students know how to apply the gas laws to
    relations between the pressure, temperature, and
    volume of any amount of an ideal gas or any
    mixture of ideal gases.
  • Boyles Law P1V1 P2V2 (Inverse)
  • Charle's Law V1/T1 V2/T2 (Direct)
  • Gay-Lussacs Law P1/T1 P2/T2 (Direct)
  • Combined Gas Law P1V1/T1 P2V2/T2

47
Standard 4
  • Students know the values and meanings of STP (0
    oC/ 273.15 K and 1 atm or 760 mmHg).
  • Students know how to convert between Celsius and
    Kelvin. (K oC 273.15)
  • Students know there is no temperature lower than
    0 Kelvin.
  • The greater the atomic and molecular motion, the
    greater the observed temperature of a substance.
  • 0 Kelvin or -273.15 oC all motion stops.
  • g. Ideal gas law PV nRT

48
Physical Characteristics of Gases
  • Gases assume the volume and shape of their
    containers.
  • Gases are the most compressible state of matter.
  • Gases will mix evenly and completely when
    confined to the same container.
  • Gases have much lower densities than liquids and
    solids.

49
A sample of chlorine gas occupies a volume of 946
mL at a pressure of 726 mmHg. What is the
pressure of the gas (in mmHg) if the volume is
reduced at constant temperature to 154 mL?
P1 x V1 P2 x V2
P1 726 mmHg
P2 ?
V1 946 mL
V2 154 mL
P2
4460 mmHg
50
A sample of carbon monoxide gas occupies 3.20 L
at 125 0C. At what temperature will the gas
occupy a volume of 1.54 L if the pressure remains
constant?
V1/T1 V2/T2
V1 3.20 L
V2 1.54 L
T1 398.15 K
T2 ?
T1 125 (0C) 273.15 (K) 398.15 K
T2
192 K
51
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52
Standard 5 Acids Bases
  • Acids, bases, salts are three classes of
    compounds that form ions in water solutions.
  • Students know the observable properties of acids,
    bases, salt solutions.
  • Acids taste sour, change color of litmus paper
    from blue to red, react w/ certain metals to
    produce hydrogen gas, react w/ strong bases to
    produce water salt.
  • Bases taste bitter, slippery, change litmus
    paper from red to blue, react w/ strong acids
    to produce water salt.

53
Standard 5
  • Students know acids are hydrogen-ion-donating and
    bases are hydrogen-ion-accepting substance.
  • Bronsted-Lowry acid-base definition acids donate
    hydrogen ions, bases accept hydrogen ions.
  • Nonmetals in the 1st 2nd rows of the periodic
    table easily dissociate to produce hydrogen ions
    b/c they have high electronegativities compared
    to hydrogen.

54
A Brønsted acid is a proton donor A Brønsted base
is a proton acceptor
acid
base
acid
base
conjugate base
conjugate acid
acid
base
55
Standard 5
  • Students know strong acids bases fully
    dissociate and weak acids and bases partially
    dissociate.
  • 1) Acids dissociate (ionize) by donating hydrogen
    ions.
  • 2) Bases dissociate (ionize) by donating
    hydroxide ions.
  • 3) Nearly complete dissociation is strong
    partial dissociation is weak.
  • 4) The strength of an acid or base can vary
    depending on temperature concentration.

56
Standard 5
  • c. Students know how to use the pH scale to
    characterize acid and base solutions.
  • 1) The pH scale measures the concentration of
    hydrogen ions (H) in solution.
  • 2) The scale is logarithmic at pH 2, the
    concentration of H is 10 xs greater than it is
    at pH 3.
  • 3) The pH scale below 0 (very acidic) to above
    14 (very basic). (0-14)
  • 4) pH values less than 7 are acidic, greater than
    7 are basic, and 7 is neutral.

57
pH A Measure of Acidity
pH -log H
Solution Is
At 250C
H OH-
neutral
H 1 x 10-7
pH 7
H gt OH-
acidic
H gt 1 x 10-7
pH lt 7
H lt OH-
basic
H lt 1 x 10-7
pH gt 7
pH 6
0.000001
1 x 10-6
pH 13
0.0000000000001
1 x 10-13
0.01
1 x 10-2
pH 2
58
Standard 6 Solutions
  • Solutions are homogeneous mixtures of two or more
    substances.
  • Students know the definitions of solute and
    solvent.
  • 1. Solute Substance present in smaller
    amounts.
  • 2. Solvent Substance present in larger amounts
  • Students know how to describe the dissolving
    process at the molecular level by using the
    concept of random molecular motion. LIKE
    DISSOLVES LIKE
  • When a solid is in contact w/ a liquid, at least
    some dissolution occurs.
  • When salts dissolve in water, positive and
    negative ions are separate and surrounded by
    polar water molecules.

59
Standard 6
  • Students know temperature, pressure, and surface
    area affect the dissolving process.
  • In a liquid solvent, solubility of gases and
    solids is a function of temperature.
  • Increasing temperature usually increases
    solubility of solid solutes but always decreases
    the solubility of gaseous solutes.
  • The solubility of a gas in a liquid is directly
    proportional to pressure.
  • Solubility describes only how much solute will
    dissolve at equilibrium, not how quickly this
    process occurs.

60
Standard 6
  • Students know how to calculate the concentration
    of a solute in terms of grams per liter,
    molarity, parts per million, and percent
    composition.
  • Grams per liter represents the mass of solute
    divided by the volume of solution.
  • Molarity describes moles of solute divided by
    liters of solution.
  • Parts per million is a ratio of one part of
    solute to one million parts of solvent (dilute
    solutions). (Units mg/L) or (x 1 million (106))
  • Percent composition is the ratio of one part of
    solute to one hundred parts of solvent. (x 100)

61
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62
Standard 7 Chemical Thermodynamics
  • Energy is exchanged or transformed in all
    chemical reactions and physical changes of
    matter.
  • Students know how to describe temperature and
    heat flow in terms of the motion of molecules (or
    atoms).
  • Temperature a measure of the average kinetic
    energy of molecular motion in a sample.
  • Heat energy transferred from a sample at higher
    temperature to one at lower temperature.
  • System (rxn boundaries) vs Surroundings (outside
    boundaries).

63
Standard 7
  • b. Students know chemical processes can either
    release (exothermic) or absorb (endothermic)
    thermal energy.
  • Breaking bonds requires energy(absorbs energy)
  • Making bonds releases energy.
  • c. Students know energy is released when a
    material condenses or freezes and is absorbed
    when a material evaporates or melts.
  • Evaporation/Melting absorb energy
  • Condensation/Freezing release energy

64
Exothermic process is any process that gives off
heat transfers thermal energy from the system
to the surroundings.
Endothermic process is any process in which heat
has to be supplied to the system from the
surroundings.
65
Standard 7
  • d. Student know how to solve problems involving
    heat flow and temperature changes, using known
    values of specific heat and latent heat of phase
    change.
  • Specific heat energy needed to change the
    temperature of one gram of substance one degree
    Celsius.
  • Latent heat of fusion (Enthalpy of fusion) Hfus
  • Latent heat of vaporization (Enthalpy of
    vaporization) Hvap

66
  • 2.      Determine the amount of heat needed (kJ)
    to completely vaporize 25.4 g of solid ice at
    26.0?C and heat the vapor to 108?C.

108
(5)
(4)
100.0
(3)
(2)
0
(1)
-26.0
Q
(mc?T)(1)
(mHfus)(2)
(mc?T)(3)
(mHvap)(4)
(mc?T)(5)
Q
(25.4 g)(2.06 J/goC)(26.0 oC)
(25.4 g)(334 J/g)
(25.4 g)(4.184 J/goC)(100.0 oC)
(25.4 g)(2260 J/g)
(25.4 g)(2.02 J/goC)(8 oC)
Q
78286 J
80 kJ
67
Standard 8 Reaction Rates
  • Chemical reaction rates depend on factors that
    influence the frequency of collision of reactant
    molecules.
  • Students know the rate of reaction is the
    decrease in concentration of reactants or the
    increase in concentration of products with time.
  • Reaction rate the rate of decrease in
    concentration of reactants or the rate increase
    in concentration of products.
  • A balanced equation expresses that the
    concentration of reactants must decrease, the
    concentration of products must increase in
    proportion to their mole ratios.

68
  • F. Reaction rate A positive quantity that
    expresses how the concentration (_________) of a
    reactant or product changes with ______. X
    concentration of X (M)
  • Units of Rate _____________
  • 1. In general
  • rate
  • 2. Example
  • rate

Molarity
time
mol/Ls
aA bB ? cC dD
N2O5 ? NO2 O2
2
4
Reactants decrease (?) over time, products
increase () over time.
coefficients
69
Standard 8
  • b. Students know how reaction rates depend on
    such factors as concentration, temperature, and
    pressure.
  • They increase the number of collisions in turn
    increasing the rate of reaction.
  • Pressure only increases reaction rate for gases.
  • c. Students know the role a catalyst plays in
    increasing the reaction rate.
  • Lowers activation energyincreasing the rate of
    reaction without being consumed.
  • Enzymes biological catalyst.
  • Catalysts are used in automobile exhaust systems
    to reduce the emission of smog-producing unburned
    hydrocarbons.

70
Standard 9 Chemical Equilibrium
  • Equilibrium is a dynamic process.
  • Concentrations remain constant.
  • Stresses cause chemical equations (rxns) to
    shift.
  • Chemical equilibrium is a dynamic process at the
    molecular level.
  • Students know how to use Le Chateliers principle
    to predict the effect of changes in
    concentration, temperature, pressure.
  • If an equilibrium system is stressed it will
    respond to partially undo the stress.
  • b. Students know equilibrium is established when
    forward and reverse reaction rates are equal.
  • Overall concentrations of each reactant and
    product remain constant over time.

71
4.63 x 10-3
Equilibrium Expression
Equilibrium Will
K gtgt 1
Lie to the right
Favor products
K ltlt 1
Lie to the left
Favor reactants
72
  • Le Chateliers Principle When a system at
    equilibrium is disturbed by applying a ______, a
    new ____________ position is attained to _______
    the stress.
  • 1. Temperature effects on equilibrium
  • Example
  • (a) STRESS Raise temperature (addition of
    ______)
  • Equilibrium is shifted ____.
  • (b) STRESS Lower temperature (removal of
    ______)
  • Equilibrium is shifted ______.

stress
equilibrium
relieve
(exothermic)
NO2 ? N2O4 58.8 kJ
2
heat
left
heat
right
73
  • 2. Pressure effects on equilibrium When
    pressure is __________, the stress is relieved by
    favoring the reaction with _______ gas molecules
    (fewer gas molecules ______ pressure).
  • Example
  • STRESS Increase pressure
  • Equilibrium is shifted _______.
  • (b) STRESS Decrease pressure
  • Equilibrium is shifted ______.

increased
fewer
lower
NO2 (g) ? N2O4 (g)
2
2 molecules on left, 1 molecule on the right
(lower pressure)
right
(fewer gas molecules)
left
(greater of gas molecules)
74
  • 3. Concentration effects on equilibrium
  • Example
  • STRESS Add NH3
  • Equilibrium is shifted _____________.
  • STRESS Add H2O
  • Equilibrium is shifted _____________.

?Acid/Base indicator
Ni(H2O)62 6 NH3 ? Ni(NH3)62 6 H2O
blue
green
Need to remove NH3
Right (blue)
Need to remove H2O
Left (green)
75
Standard 10 Organic and Biochemistry
  • The bonding characteristics of carbon allow the
    formation of many different organic molecules of
    varied sizes, shapes, and chemical properties and
    provide the biochemical basis of life.
  • Students know large molecules (polymers), such as
    proteins, nucleic acids, and starch, are formed
    by repetitive combinations of simple subunits
    called monomers.
  • Ex. Starch is made from a number of simple sugar
    molecules (glucose) joined together.

76
Standard 10
  • b. Students know the bonding characteristics of
    carbon that result in the formation of a large
    variety of structures ranging from simple
    hydrocarbons to complex polymers and biological
    molecules.
  • Carbon can form 4 bonds.
  • 2) Carbon can form single, double, triple
    bonds which determine the geometry of the
    molecules.

77
Standard 10
  • 3) Hydrocarbons (Carbon Hydrogen only) ie.
    methane (CH4) ethane (C2H6)
  • 4) Biological molecules protein
  • Manufactured polymers polyester, nylon,
    polyethylene.
  • Polymers A polymer is a compound with a
    repeating unit, called a monomers and contains a
    high molar mass.

78
Standard 10
  • c. Students know amino acids are the building
    blocks of proteins.
  • Proteins large single-stranded polymers often
    made up of thousands of relatively small subunits
    called amino acids.
  • Peptide bonds attach amino acids.
  • Amino acids vary in composition giving them
    different shapes and functions (R-group).
  • DNA is the blueprint for building proteins.

79
Standard 11 Nuclear Processes
  • Nuclear processes are those in which an atomic
    nucleus changes, including radioactive decay of
    naturally occurring and human-made isotopes,
    nuclear fission, and nuclear fusion.
  • Students know protons and neutrons in the nucleus
    are held together by nuclear forces that overcome
    the electromagnetic repulsion between the
    protons. (Nuclear binding energy)

80
Standard 11 Nuclear Processes
  • b. Students know the energy release per gram of
    material is much larger in nuclear fusion or
    fission reactions than in chemical reactions.
    The change in mass (E mc2) is small but
    significant in nuclear reactions.
  • Fusion 2 nuclei come together to form a heavier
    nucleus.
  • Fission a heavy nucleus splits to form two
    lighter nuclei.
  • Nucleon term for a proton or neutron.
  • Fusion/Fission produce one million times more
    energy than chemical reactions.

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Atomic number (Z) number of protons in nucleus
Mass number (A) number of protons number of
neutrons
atomic number (Z) number of neutrons
A
1
1
0
0
4
Z
1
0
-1
1
2
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Standard 11
  • c. Students know some naturally occurring
    isotopes of elements are radioactive, as are
    isotopes formed in nuclear reactions.
  • Isotopes atoms with the same number of protons
    but a different number of neutrons.
  • (C-12, C-13, C-14)
  • 2) Parent isotopes less stable isotopes of one
    element that undergo radioactive decay,
    transforming to more stable isotopes called
    daughter products.

83
Standard 11
  • d. Students know the three most common forms of
    radioactive decay (alpha, beta, gamma) and know
    how the nucleus changes in each type of decay.
  • Radioactive isotopes transform to more stable
    isotopes, emitting particles from the nucleus.
  • Alpha emit helium-4, beta emit electrons or
    positrons, gamma emits high-energy
    electromagnetic.
  • Alpha decay forms isotopes w/ 2 less protons and
    2 less neutrons.
  • Beta decay forms elements w/ the same of
    nucleons but one less or more protons.
  • Gamma decay does not change the number of
    nucleons in the nucleus but lowers the energy
    state.

84
212Po decays by alpha emission. Write the
balanced nuclear equation for the decay of 212Po.
212 4 A
A 208
84 2 Z
Z 82
85
Nuclear Stability and Radioactive Decay
Beta decay
Decrease of neutrons by 1
Increase of protons by 1
Gamma decay
86
n/p too large
beta decay
n/p too small
positron decay or electron capture
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Standard 11
  • e. Student know alpha, beta, gamma radiation
    produce different amounts and kinds of damage in
    matter and have different penetrations.
  • They are ionizing radiation which can ionize as
    many as ½ million atoms.
  • Alpha particles shortest range and can penetrate
    a few millimeters of paper.
  • Beta particles longer ranges and can penetrate
    several centimeters of aluminum.
  • Gamma rays can penetrate matter up to several
    meters of lead.
  • These 3 types of radiation interact w/ matter by
    losing energy and ionizing surrounding atoms.

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Observations
Hypothesis
Summarizes the results of many observations and
experiments.
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Important Points KNOW THE FOLLOWING!
  • Ionization energy is lowest in group 1.
  • Nuclear Binding energy Nuclear forces holding
    the nucleus
  • PV nRT
  • Temperature Average Kinetic energy
  • pH scale 0 (acid) to 14 (base)
  • Gas molecules move randomly diffusion
  • Radioactive gives of alpha, beta gamma
  • 1 mole 6.02 x 1023
  • Equilibrium forward and reverse same rate
  • Le Chatliers Principle Temp/Pressure/Concentrat
    ion
  • Ionic bond Cation anion electrostatic
  • Road Map
  • Periodic table Lft to Rt increase atomic or
    of protons.

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Contd
  • Lewis structure full octet
  • ? H -- strong acid
  • Nucleus is small but dense
  • Gas Laws PV V/T P/T
  • Atom becomes an ion by gaining or losing
    electrons
  • Electronegativity High difference is ionic Low
    diff is covlaent
  • Endothermic rxn absorbs energy from surroundings
    (feels cold)
  • Exothermic rxn release energy into the
    surroundings (feels hot)
  • Acids are sour and react w/most metals to produce
    H2(g).
  • Increased collisions lead to increased pressure.
  • Catalyst lows activation energy
  • Parts Per Million (ppm) mg/L ( is parts per
    100).
  • Acids turn litmus paper from blue to red Blue to
    Red Acid

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