SNC 1DO LESSON PLANS

Ontario Curriculum objectives: U=understanding concepts (U1-U15) D=developing skills  (D1-D10) R=relating science (R1-R4)

Text: Sciencepower 9, McGraw-Hill

PHYSICAL PROPERTIES: property detected using five senses
            -hardness: rate hardness on scale from 1 to 10 (talc=1, diamond=10)
            -texture: how does it feel? (smooth, rough)
            -clarity: how well does it transmit light? (transluscent: some light reflected, absorbed, transmitted/ transparent: light transmitted/
             opaque: light absorbed or reflected)
            -malleability: ability to be hammered into foil (tin, gold, aluminum are very malleable)
            -ductility: ability to form wire (copper, aluminum have good ductility)
            -viscosity: poor ability to flow (high viscosity in syrup, low viscosity in water)
            -odour: how does it smell (putrid, sweet) ONLY do when instructed to waft gas, which will not be often
            -taste: (sweet, sour, bitter, salty) NEVER taste materials in science class
            -density: Density =Mass/Volume
            -state: (solid, liquid, gas)
            -colour: (red, orange, yellow, green, blue, indigo, violet, brown, colourless, black, white)

CHEMICAL PROPERTIES: ability to form new chemicals with new physical properties 

        eg. Sugar (some physical properties: white, solid, sweet)
           Sulphuric Acid (some physical properties: clear, colourless, liquid)
        These are REACTANTS: chemicals entering  a reaction
        Carry out this reaction as a demonstration for the class...
        PRODUCTS: chemicals made by this reaction are described
                    Carbon (some physical properties: black, solid, brittle)
                    Water (some physical properties: clear, colourless, odourless, liquid)
Sugar has the chemical property of being able to form Carbon and Water with the help of Sulphuric Acid

CHEMICAL FORMULAS: element symbols are written with letter for each element, and subscript afterwards to show numbers of atoms of each element in a molecule(molecules are combinations of atoms). These formulas do not change for substances unless chemical reaction occurs
                                           H₂ is the chemical formula for a molecule of hydrogen (H) containg two hydrogen atoms.
Ones are not written in chemical formulas but are assumed if no subscript is shown
                                           H₂O has 2 H (hydrogen), 1 O (oxygen)
                                           H₂SO₄  has 2 H (hydrogen), 1 S (sulphur) and 4 O (oxygen)
A number in front of formula affects everything in the formula by multiplying it
                                           6 H₂O has 12 H (hydrogen), 6 O (oxygen) 
A subscript after a bracket multiplies everything in the bracket only
                                           Be(OH)₂ has 1 Be (beryllium), 2 O (oxygen) and 2 H (hydrogen)

Additional subscripts with letters found after the chemical formula indicate the state of the molecule
                                          (s) = solid,                          eg. Ni_(s) = solid nickel
                                          (g) = gas,                           eg. O_2(g) = oxygen gas
                                          (l) = liquid,                         eg. H₂O_(l) = liquid water
                                          (aq) = dissolved in water,  eg. NaCl_(aq) = salt dissolved in water

CHEMICAL EQUATIONS: a chemical reaction is shown using words or symbols for reactants and products

word equations: full chemical names of reactants and products are written, with an arrow in between to show the direction of the reaction from starting reactants to finished products

reactant names  ---> product names

                                   sugar -----> carbon + water

This word equation could also be written as:
                                   sugar -----> water + carbon

symbol equations: chemical formulas of reactants and products are written

reactant formulas ---> product formulas

                                  C₆H₁₂O_6(s) ----> C_(s) + H₂O_(l)

This symbol equation could also be written as:

                                  C₆H₁₂O_6(s) ----> H₂O_(l) + C_(s)

GAS TESTS: The gases hydrogen, oxygen and carbon dioxide can be detected using the following tests...

Hydrogen gas causes a burning spint to pop (an explosive reaction occurs which produces water)

Oxygen gas causes a glowing splint to burst into flame (oxygen allows combustion but is not explosive)

Carbon dioxide gas causes a burning splint to go out and makes limewater cloudy

Observations: recorded facts/data
Law: generalization of many observations
Theory: explanation of observations (model)

KINETIC MOLECULAR THEORY (KMT or PARTICLE THEORY)
-all matter consists of small particles
-all particles of one substance are identical
-spaces between molecules are large compared to particle size
-particles attract one another
-particles are constantly in motion (movement increases with heat)

KMT can be used to explain states of matter:

SOLID - particles very close, strongly attracted and only moving by vibration
LIQUID - particles are in clumps, with weaker attraction, moving faster and sliding over each other
GAS - particles have broken off on their own, with very little attraction, moving very fast and spreading out to fill their container

CHANGES OF STATES OF MATTER

GAS --> LIQUID (energy loss, condensation)
GAS --> SOLID (energy loss, sublimation)
LIQUID --> GAS (energy gain, evaporation)
LIQUID --> SOLID (energy loss, freezing)
SOLID --> LIQUID (energy gain, melting)
SOLID --> GAS (energy gain, sublimation)

DEFINITIONS OF TEMPERATURE AND HEAT

temperature - average molecule speed (faster movement in molecules results in higher temperatures)
heat - energy used to break attraction OR speed molecules up

THEORY:  matter is made of atoms
                atoms of an element are identical
                molecules are group of atoms
                atoms cannot be divided

EVIDENCE:     found mass of reactants  = mass of reactants
                      proposed that atoms just reformed as new molecules during chemical reactions

Formulas:     Carbon dioxide = CO₂
                     Water = H₂O
                     Oxygen = O₂
                     Methane = CH₄

Chemical Reaction of Burning Methane:
Methane        +         Oxygen    --------->    Water          +        Carbon Dioxide
   CH₄            +            2O₂         --------->    2H₂O            +        CO₂ 

What goes into the reaction must come out, but the atoms are rearranged to form new molecules 

REACTANT ELEMENTS                                                                      PRODUCT ELEMENTS
C        H        O                                                                                    C        H       O
1         4        4                                                                                     1         4       4 

Rearrange plastic models of these atoms to show reactants and products of burning methane

Molecules: groups of atoms with their own properties joined by chemical bonds

THEORY: "blueberry muffin model" of an atom proposed (also called "plum pudding model" and a variety of similar names)
                -atoms can be divided
                -electrons are negative, and placed in and atom with a spread out positive charge

EVIDENCE: electrons removed from atoms bent towards a positive charge in a cathode ray tube
                    (as opposite charges attract, electrons must be negative)

ERNEST RUTHERFORD (research done around the year 1900)

THEORY: "nuclear atom" model of an atom proposed
                -negative electrons surround a small, dense, positive nucleus (protons are positive)

EVIDENCE: alpha particles with posistive charge sometimes bounced off gold foil in a lab experiment
                        -this indicated a dense positive charge in the gold (the protons in the nucleus) as like
                         charges repel and the positive alpha particles were being repelled by something dense
                         inside the gold atoms (pg. 239)
 

Teachers should distribute periodic tables to students.

THEORY: "Bohr-Rutherford" model of atoms
                    -positive nucleus in center of atom containing protons
                     (neutral "neutrons" were later discovered to be in this nucleus as well)
                    -electrons orbit in shells around the nucleus
                    -electorns with greater energy are found in higher orbits

EVIDENCE: electrons, when given energy, jump to higher shells
                        -as electrons lose this energy again, they drop back down to lower levels
                        -different amounts of energy loss is indicated by different colours of light produced by the atoms, called a light spectra
                        -each atom has a certain number of electrons which will produce a certain light spectra

                                          (u = atomic mass unit)
PART            LOCATION                MASS                    CHARGE
electron(e-)    shells                         0 u                     negative
protons(p+)    nucleus                      1 u                     positive
neutrons(no)  nucleus                      1 u                     no charge -neutral

EXAMPLE:

²³Na          
¹¹

This tells us  that 23 =atomic mass (larger number),
                           11 =atomic number (smaller number)
                           Na =chemical symbol

atomic number = # of protons AND # of electrons in a neutral atom (positive will balance out the negative)

mass number - atomic number = # of neutrons (most of the atoms mass is made of the protons and neutrons, not the electrons)

For the above atom:
protons = 11 (atomic number)
electrons = 11 (atomic number)
neutrons = 23 - 11 = 12 (mass number - atomic number)
symbol = sodium

2e- fit in first shell
8e- fit in second shell
8e- fit in third shell
2e- fit in last shell

Bohr-Rutherford model only works for first 20 elements, as it cannot fit more than 20 electrons
-fill first electon shell first, then work at filling outer layers as needed

¹H        p+ = 1, no = 0, e- = 1, Hydrogen Atom
¹

Worksheets on elements and compounds:

Elements consist of one type of atom, Compounds consist of two or more types of atoms chemically bonded.
Both elements and compounds are pure substances as they cannot be broken down or altered by physical changes.

ATOMS    - atoms have protons, neutrons and electrons

                -atoms with different numbers of PROTONS:
                                            -have different atomic numbers
                                            -are different elements (the number of protons defines the type of element)

              ¹²C    =    6p+, 6e-, 6no, Carbon atom
            ^{6 
              14}N    =    7p+, 7e-, 7no, Nitrogen atom
            ⁷
                -atoms with different numbers of NEUTRONS (but same atomic number):
                                            -are called ISOTOPES
                                            -have different atomic mass, but are the same element
          ¹²C    =    6p+, 6e-, 6no, 12 u Carbon atom
            ^{6
          14}C    =    6p+, 6e-, 8no, 14 u Carbon atom
            ⁶

                -atoms with different numbers of ELECTRONS (but the same atomic number):
                                            -are called IONS if charged
                                            -have 0 charge if # of e- = # of p+
                                            -have +1 charge for each e- lost (e- < p+)
                                            -have -1 charge for each e- gained (e- > p+)
          ¹²C⁺¹    =    6p+, 5e-, 6no, +1 charge, Carbon Atom
             ^{6
          12}C        =    6p+, 6e-, 6no, 0 charge, Carbon Atom
            ^{6
          12}C^-2    =    6p+, 8e-, 6no, -2 charge, Carbon Atom
            ⁶

METALS   -84 of 109 elements are metals
                -shiny, lustre, good conductors of heat and electricity
                -malleable (forms sheets), ductile (forms wires)
                -all are solids at room temperature, except liquid Hg (mercury)
NONMETALS -25 nonmetals
                -poor conductors of electricity and heat
                -not shiny, solids are brittle
                -most are gas or solid at room temperature, except brown liquid Br (bromine)
METALOIDS -have properties of metals and nonmetals
                -eg. Graphite (C) can conduct electricity well, but is brittle

Metals -trends found moving left and down on periodic table = boiling point lowers, reactivity increases
            Columns on the periodic table are located side by side and often called "families" because of properties they share
            First column on the left  = Alkaline metals
            Second column on the left  = Alkaline Earth metals

Nonmetals - trends found moving right and up on the periodic table = boiling point lowers, reactivity increases
            Second last column on the right = Halogens
            Last Column to right= NOBLE GASES, which do not react well with anything, All are gases.

VALENCE ELECTRONS: electrons in outer shell are called valence electrons
                                        -each COLUMN (vertical) or FAMILY has the same number of valence electrons
                                         and this results in them having the same basic properties
-electrons in outer shell must fill outer shell in order for the atom to be stable
-chemical reactions occur when e- are gained or lost to fill the outer valence shell

NOBLE GASES
                    -this family is stable/not reactive because they already have full outer valence shells,
                                      eg. He has 2 valence e-
                                           -all other noble gases have 8 valence e-
ALKALINE METALS
                    -this family has 1 valence e-
                    -these atoms must lose 1e- or gain 7e- to fill their outer shell (it is easier to lose 1e-)
                    -these atoms react by losing 1e- (next family lose 2e-, next 3e-,...etc)
                    -these are the most reactive metals (need to lose least # of e-)

ALKALINE EARTH METALS
                    -this family has 2 valence e-
                    -these atoms must lose 2 e- or gain 6 e- to fill their outer shell (it is easier to lose 2e-)
                    -these atoms react by losing 2e-

HALOGENS
                    -this family has 7 valence e-
                    -these atoms must gain 1e- or lose 7e- to fill their outer shell (easier to gain 1e-)
                    -react by gaining 1e- (next family gains 2e-, next 3e-,...etc)
                    -these are the most reactive non-metals (need to gain least # of e-)

IONIC BONDS -one atom gives another atom electrons
                      -resulting opposite charges pull atoms together (as opposite charges attract)
                      -these atoms are now said to be "bonded" or joined by this ionic bond
                      -this type of bond generally joins a metallic atom to a non-metallic atom

eg. Li (an alkaline metal) gives e- to F (a halogen), so Li is positive (lost e-) and F is negative (gained e-)
      Li+ is attracted to F-.  so an LiF molecule formed using this attraction as an ionic bond

-atoms sometimes share e- in order to fill their valence shells
-the bond that joins the atoms together is the shared electron pair
-covalent bonds generally join non-metallic atoms to each other

eg. F (a halogen) needs one e- to fill the valence shell, so it shares 1e- with another F
      F₂ molecule results, as these atoms share a pair of electrons in a covalent bond

MIXTURES: have variable composition, unlike pure substances
                    -can be separated by physical means
                    -variable temperature during changes of state, as each substance in the mixture has it's own melting/boiling point

There are two types of mixtures:

            SOLUTIONS (homogeneous)      -2 or more components
                                                              -1 phase (or visible part) as one substance (solute) is dissolved in another (solvent)

            HETEROGENEOUS MIXTURES    -2 or more components
                (mechanical mixtures)           -2 or more phases

PURE SUBSTANCES    -fixed composition
                                        -cannot be separated by physical means
                                        -constant temperature during changes of state

There are two types of pure substances: 

                ELEMENTS    -simplest pure substance
                                        -cannot be decomposed (not separated chemically)

                COMPOUNDS     -composed of 2 or more elements
                                            -can be decomposed (chemically separated

FLOW CHART FOR SEPARATION of marbles, sand, salt, water

i) Method: sieve the marbles, sand, salt, water

go through                                  stop
(salt, sand, water)                   (marbles have been separated)

ii) Method: filter the sand, salt, water

filtrate                                         residue
(salt, water)                            (sand has been separated)

iii) Method: distil the sand, salt, water

recondense                                residue
(water has been separated)   (salt has been separated)

Separate mixture provided by teacher in lab...
i)construct a flowchart
ii) follow procedure on the flowchart in the lab
iii) return separated material to front of lab