Physical Science

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Unit 1

• Physical Science
• -
• Atoms and Elements

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• Nature of Science
• "is the search for the truth
• First Nations perspectives
• Medicine Wheel
• Four directions
• Four Elements

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• Early Civilization perspectives
• Greek Elements
• Chemistry started with Democritus

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• Classifying Matter
• Forms of Matter
• Mass
• Volume
• Four States Solid, Liquid, Gas, Plasma

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• Classifying Matter
• Work in a group of 2 or 3 to discuss the
  following and complete the activity. Why did you
  place the substances where you did?

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• Classifying Matter
• Forms of Matter
• Mass
• Volume
• Four States Solid, Liquid, Gas, Plasma
• Pure Substances
• Elements
• Compounds
• Mixtures
• Mechanical mixture
• Suspension
• Solution

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• Physical Properties
• Three physical states of matter
• Melting Evaporation
• -----? -----?
• SOLID LIQUID GAS
  ?----
  ?-----
• Freezing Condensation
• Water is unique

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• Physical Properties of Matter
• Colour and lustre
• Melting point
• Boiling point
• Density
• Solubility
• Ductility
• Crystal Shape
• Conductivity
• Hardness
• Texture
• Malleability

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• Chemistry
• is the study of the composition and properties of
  matter
• Chemists interested in
• 1) composition and structure of substances
• 2) the properties of these substances
• 3) the conditions under which these substances
  change to form new ones

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• Chemical Properties
• Chemical Change
• Chemical Reaction
• Takes heat energy or light
• Combustion
• Controlled Change
• Traditional uses preserving foods
• Medicines herbs and plants
• Polyethylene Plastics

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• Models of Matter
• Indirect Evidence
• how do we know when we cant see or touch?
• Theory vs. Law
• theory - an explanation of an event that has been
  supported by consistent, repeated experimental
  results and has therefore been accepted by the
  majority of scientists.
• law - an action or condition that has been
  observed so consistently that scientists are
  convinced that it will always happen.

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Subatomic Particles

• We are interested in three particles and their
  mass, charge, and location.
• AMU Atomic Mass Unit

Mass Charge Location
Proton 1 AMU In Nucleus
Neutron 1 AMU Neutral In Nucleus
Electron 1/1836 AMU - Outside Nucleus
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• Models of Matter
• Remember began with the Greeks
• - Democritus
• Then Alchemists
• Finally Modern Chemistry Begins

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Models of the Atom
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Models of the Atom

• Different Ways of Understanding
• 1) Greeks (Democritus) 400 B.C.

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• 2) Dalton 1803
• A small particle with several smaller pieces
  within.

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• 3) Thomson 1898
• The Plum Pudding Model

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• 4) Rutherford 1911
• Concentric Rings

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• 5) Bohr 1923

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• 6) Scroedinger Present
• Quantum Mechanical Model
• Based on the probability of where electrons
  would be found about the nucleus.

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• Elements and Compounds
• Properties of Metals
• Low melting points mean low strength
• Creating alloys
• Properties of Non-metals
• Do not conduct electricity
• Could be solid, liquid, or gas
• Properties of Metalloids
• Both metallic and non-metallic properties
• Are semi-conductors of electricity

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• Element Symbols
• Short way of representing
• Represents 1 atom in a chemical formula
• Many based on the Latin name
• Some Common Elements
• Iron
• Carbon
• Hydrogen
• Oxygen
• Sodium
• Chlorine

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• Compounds
• are a combination of two or more elements
• Ionic Compounds
• when an atom loses an electron, it becomes
  positive which is known as a cation.
• when an atom gains an electron, it becomes
  negative which is known as an anion.
• Cations and anions are attracted to each other
  and thus come together to form a compound.

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• Potassium is losing an electron and becomes
  positively charged.
• Chloride is gaining an electron and becomes
  negatively charged.
• K and Cl now attract each other.
• The compound has a neutral charge.

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• Molecular Compounds
• Are pure substances from non-metal elements.
• Form covalent bonds
• shared electrons

The two Hydrogen atoms share their outer
electrons with the Oxygen atom to form H20.
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• Chemical Formulas and Names
• H H O ? H2O
• Hydrogen (2 atoms) and oxygen (1 atom)
• Combine to form Water (1 molecule)

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Periodic Table
Atomic Number Tells us the number of protons
16 S Sulfur 32.06
Element Symbol
Element Name
Atomic Mass tells us the number of neutrons and
protons
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Periodic Table
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• In an atom/element the number of protons is
  always equal to the number of electrons.
• We always round the atomic mass to the nearest
  whole number.
• Neutrons Atomic Mass - Atomic Number

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• Ions
• ions are formed when an electron is either gained
  or lost.
• when an electron is gained, it becomes a negative
  ion and we call this an anion.
• when an electron is lost, it becomes a positive
  ion and we call this a cation.

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• When naming a cation, simply add the word 'ion'
  to the end of the element name.
• Ex//
• Mg - Magnesium ? Mg2 - Magnesium ion
• Ca - Calcium ? Ca2 - Calcium ion
• Na - Sodium ? Na1 - Sodium ion

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• When naming an anion, drop the last few letters
  of the element name and add the ending -ide.
• Ex//
• O - Oxygen ? O-2 Oxide
• N Nitrogen ? N-3 - Nitride
• Cl - Chlorine ? Cl-1 Chloride
• ions become charged because they want 8 electrons
  in their outer shell (octet)

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• When an anion and a cation come
  together, they form a compound.

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• NAMING
• the cation always goes first, followed by the
  anion.
• use the element name for the cation.
• use the ion name for the anion.
• 1. a) Li1 P-3
• b) Mg2 F-1
• c) Ca2 N-3
• d) Cu2 O-2
• e) Cr3 S-2
• f) Fe2 S-2
• g) Ag1 S-2
• h) Al3 Br-1
• i) Fe3 O-2

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Cl-1 O-2 N-3
K1 KCl Potassium Chloride K2O Potassium Oxide K3N Potassium Nitride
Ca2 CaCl2 Calcium Chloride CaO Calcium Oxide Ca3N2 Calcium Nitride
Cr3 CrCl3 Chromium (III) Chloride Cr2O3 Chromium (III) Oxide CrN Chromium (III) Nitride
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• 2. Write the chemical formula for each of the
  following compounds.
• Potassium chloride
• Calcium nitride
• Copper (II) oxide
• Iron (III) bromide
• Magnesium phosphide
• Aluminum selenide
• Chromium (III) sulfide
• Tin (II) oxide

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• 3. Name each of the following compounds.
• a) Li2O
• b) Ag3N
• c) SnO2
• d) CrCl3
• e) BaS
• f) Fe2O3
• g) Cu3P
• h) V2O5

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G. Writing Equations

• Products
• - are the chemicals that are made or produced in
  a chemical reaction
• Reactants
• - are the chemicals that begin or go into the
  reaction before it takes place

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• Chemical Reaction
• - when the chemicals that go into the reaction
  change and new products (chemicals) are formed.
• Ex. MgI2 Na2O ? NaI MgO
• Reactants Products
• When we write the compounds, we must make sure
  that they are balanced.

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• tells us that two compounds are combining.
• Key Words combines, mixes, reacts, and, etc.
• ? acts as an equals sign to separate
  reactants and products.
• Key Words to form, to produce, to make,
  synthesize, decompose, break down, etc.

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Sample Problems

• 1) Magnesium bromide reacts with calcium nitride
  to form magnesium nitride and calcium bromide.
• 2) Copper (II) oxide reacts with lithium
  phosphide and produces copper (II) phosphide and
  lithium oxide.

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• 3) Tin (IV) sulfide reacts with calcium iodide
  and makes tin (IV) iodide and calcium sulfide.
• 4) Lithium chloride decomposed to form lithium
  and chlorine.
• Magic Seven if ever the following elements are
  by themselves, they are found in pairs
  (diatomic).
• N2, O2, F2, Cl2, Br2, I2, At2, H2

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• 5) Calcium reacts with iodine to form calcium
  iodide.
• 6) Chromium (III) iodide combines with sodium
  phosphide to make chromium (III) phosphide and
  sodium iodide.

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H. Writing Word Equations

• Examples
• 1) CaI2 Al2O3 ? CaO AlI3

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• 2) CrI2 Cu2S ? CrS CuI
• 3) Fe2O3 KF ? FeF3 K2O

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I. Acids and Bases
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• Acids
• Have a sour taste
• Very corrosive
• Neutralize bases
• Conduct electricity very well
• Dissolve in water to produce hydrogen ions (H)
  in solution
• When an acid and a base neutralize each other,
  they form salt and water
• NaOH HCl ? H2O NaCl
• Sodium Hydrochloric Water Salt
• Hydroxide Acid

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• Bases
• Have a bitter taste
• Very corrosive
• Neutralize acids
• Conduct electricity very well
• Dissolve in water to produce hydroxide ions (OH-)
  in solution
• When an acid and a base neutralize each other,
  they form salt and water

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• Acid-Base Indicators
• Acid Base indicators are substances that change
  different colors when added to acids and bases.
• Litmus Paper red in an acid
• - blue in a base
• Bromothymol Blue yellow in an acid
• - blue in a base

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• pH paper is another type of indicator that can
  change to several different colours to tell the
  scientist how acidic or basic the solution is.

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• pH Scale
• An acid-base indicator will not tell you how
  acidic or basic a solution is.
• The pH scale indicates the level of acidity of a
  solution and it ranges from 0-14.
• pH of 0-6.9 is acidic.
• pH of 7 is neutral.
• pH of 7.1-14 is basic.
• The pH scale is logarithmic (based on the power
  of ten). This means the difference between a pH
  of 5 and 6 is actually ten times. The difference
  between 4 and 6 is actually 100 times.

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• Maintaining a constant pH is often very important
  for biological systems.
• Human blood has a pH range of 7.35-7.45. Any
  change from this could be fatal.
• Plants grow best in soil with a pH between 6 and
  7. Any higher or lower, prevents the plants from
  absorbing nutrients.
• Shampoo normally has a pH of about 8. The human
  scalp has a pH of about 6. A scalp that becomes
  too basic results in dandruff.

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THE END