Unit 1Unit 1

Physical Science Physical Science

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Atoms and ElementsAtoms and Elements

Nature of ScienceNature of Science"is the search for the truth“"is the search for the truth“

First Nations perspectivesFirst Nations perspectives• Medicine WheelMedicine Wheel• Four directionsFour directions• Four ElementsFour Elements

Early Civilization perspectivesEarly Civilization perspectives• Greek ElementsGreek Elements• Chemistry started with DemocritusChemistry started with Democritus

ChemistryChemistry is the study of the composition and is the study of the composition and properties of matterproperties of matter

Chemists interested inChemists interested in::1) composition and structure of 1) composition and structure of

substancessubstances2) the properties of these substances2) the properties of these substances3) the conditions under which these 3) the conditions under which these

substances change to form new onessubstances change to form new ones

Forms of MatterForms of Matter•MassMass•VolumeVolume•Four States: Solid, Liquid, Gas, PlasmaFour States: Solid, Liquid, Gas, Plasma

Classifying MatterClassifying Matter• Matter has ‘property’Matter has ‘property’

Pure SubstancesPure Substances• ElementsElements• CompoundsCompounds

MixturesMixtures• Mechanical mixtureMechanical mixture• SuspensionSuspension• SolutionSolution

Using mixtures in miningUsing mixtures in mining

Physical PropertiesPhysical Properties• Water is uniqueWater is unique

Physical PropertiesPhysical Properties• Colour and lustreColour and lustre• Melting pointMelting point• Boiling pointBoiling point• DensityDensity• SolubilitySolubility• DuctilityDuctility• Crystal ShapeCrystal Shape• ConductivityConductivity• HardnessHardness• TextureTexture• MalleabilityMalleability

Chemical PropertiesChemical Properties• Change and ReactionChange and Reaction• Takes heat energy or lightTakes heat energy or light

CombustionCombustionControlled ChangeControlled Change

• Traditional uses – preserving foodsTraditional uses – preserving foods• Medicines – herbs and plantsMedicines – herbs and plants

Polyethylene PlasticsPolyethylene Plastics

Models of MatterModels of Matter

Remember: began with the Greeks Remember: began with the Greeks

- Democritus- Democritus

Then: AlchemistsThen: Alchemists

Finally: Modern Chemistry BeginsFinally: Modern Chemistry Begins

Models of the AtomModels of the Atom

Different Ways of UnderstandingDifferent Ways of Understanding

1) Greeks (Democritus) – 400 B.C.1) Greeks (Democritus) – 400 B.C.

2) Dalton – 18032) Dalton – 1803

A small particle with several A small particle with several smaller pieces within.smaller pieces within.

3) Thompson – 18983) Thompson – 1898

The Plum Pudding ModelThe Plum Pudding Model

4) Rutherford – 19114) Rutherford – 1911

Concentric RingsConcentric Rings

5) Bohr – 19235) Bohr – 1923

6) Scroedinger – Present6) Scroedinger – Present

Quantum Mechanical ModelQuantum Mechanical Model

Based on the probability of Based on the probability of where electrons would be found where electrons would be found about the nucleus.about the nucleus.

D. D. Subatomic ParticlesSubatomic Particles

We are interested in three particles We are interested in three particles and their mass, charge, and location.and their mass, charge, and location.

AMU – Atomic Mass UnitAMU – Atomic Mass Unit

MassMass ChargeCharge LocationLocation

ProtonProton 1 AMU1 AMU ++ In NucleusIn Nucleus

NeutronNeutron 1 AMU1 AMU NeutralNeutral In NucleusIn Nucleus

ElectronElectron 1/1836 1/1836 AMUAMU

-- Outside Outside NucleusNucleus

In an atom/element the number In an atom/element the number of protons is always equal to the of protons is always equal to the number of electrons.number of electrons.

We always round the atomic We always round the atomic mass to the nearest whole mass to the nearest whole number.number.

# Neutrons = Atomic Mass - Atomic Number# Neutrons = Atomic Mass - Atomic Number

16

SSulfur

32.06

Atomic Number – Tells us the number of protons

Element Symbol

Element Name

Atomic Mass – tells us the number of neutrons and protons

E. E. IonsIons ions are formed when an ions are formed when an

electron is either gained or lost.electron is either gained or lost. when an electron is gained, it when an electron is gained, it

becomes a negative ion and we becomes a negative ion and we call this an anion.call this an anion.

when an electron is lost, it when an electron is lost, it becomes a positive ion and we becomes a positive ion and we call this a cation.call this a cation.

When naming a cation, simply add the When naming a cation, simply add the word 'ion' to the end of the element word 'ion' to the end of the element name.name.

Ex// Ex//

Mg - Magnesium Mg - Magnesium Mg Mg+2+2 - Magnesium ion - Magnesium ion

Ca - Calcium Ca - Calcium Ca Ca+2+2 - Calcium ion - Calcium ion

Na - Sodium Na - Sodium Na Na+1+1 - Sodium ion - Sodium ion

When naming an anion, drop the last few When naming an anion, drop the last few letters of the element name and add the letters of the element name and add the ending -ide.ending -ide.

Ex// Ex//

O - Oxygen O - Oxygen O O-2-2 – Oxide – Oxide

N – Nitrogen N – Nitrogen N N-3 -3 - Nitride - Nitride

Cl - Chlorine Cl - Chlorine Cl Cl-1-1 – Chloride – Chloride

ions become charged because they want 8 ions become charged because they want 8 electrons in their outer shell (octet)electrons in their outer shell (octet)

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

F. F. Compounds (Ionic)Compounds (Ionic)

CompoundsCompounds are a combination of two or are a combination of two or more elementsmore elements

when an atom loses an electron, it when an atom loses an electron, it becomes positive which is known as a becomes positive which is known as a cation.cation.

when an atom gains an electron, it when an atom gains an electron, it becomes negative which is known as becomes negative which is known as an anion.an anion.

Cations and anions are attracted to Cations and anions are attracted to each other and thus come together to each other and thus come together to form a compound.form a compound.

• Compounds must be balanced so that the positive charges balance the negative charges.• Compounds must also be written in lowest possible form.

NAMINGNAMING the cation always goes first, followed by the the cation always goes first, followed by the

anion.anion. use the element name for the cation.use the element name for the cation. use the ion name for the anion.use the ion name for the anion.

1. 1. a) a) LiLi+1+1 PP-3-3

b) b) MgMg+2+2 FF-1-1

c) c) CaCa+2+2 NN-3-3

d) d) CuCu+2+2 OO-2-2

e)e) CrCr+3+3 SS-2-2

f) f) FeFe+2+2 SS-2-2

g) g) AgAg+1+1 SS-2-2

h) h) AlAl+3+3 BrBr-1-1

i) i) FeFe+3+3 OO-2-2

ClCl-1-1 OO-2-2 NN-3-3

KK+1+1

KClKCl

Potassium Potassium ChlorideChloride

KK22OO

Potassium Potassium OxideOxide

KK33NN

Potassium Potassium NitrideNitride

CaCa+2+2

CaClCaCl22Calcium Calcium ChlorideChloride

CaOCaO

Calcium Calcium OxideOxide

CaCa33NN22

Calcium Calcium NitrideNitride

CrCr+3+3

CrClCrCl33Chromium Chromium

(III) (III) ChlorideChloride

CrCr22OO33

Chromium Chromium (III) Oxide(III) Oxide

CrNCrN

Chromium Chromium (III) (III)

NitrideNitride

2. Write the chemical formula for each 2. Write the chemical formula for each of the following compounds.of the following compounds.

a)a) Potassium chloridePotassium chloride

b)b) Calcium nitrideCalcium nitride

c)c) Copper (II) oxideCopper (II) oxide

d)d) Iron (III) bromideIron (III) bromide

e)e) Magnesium phosphideMagnesium phosphide

f)f) Aluminum selenideAluminum selenide

g)g) Chromium (III) sulfideChromium (III) sulfide

h)h) Tin (II) oxideTin (II) oxide

3. Name each of the following compounds.3. Name each of the following compounds.

a) Lia) Li22OO

b) Agb) Ag33NN

c) SnOc) SnO22

d) CrCld) CrCl33e) BaSe) BaS

f) Fef) Fe22OO33

g) Cug) Cu33PP

h) Vh) V22OO55

G. Writing EquationsG. Writing Equations

ProductsProducts

- are the chemicals that are made or - are the chemicals that are made or produced in a chemical reactionproduced in a chemical reaction

ReactantsReactants

- are the chemicals that begin or go - are the chemicals that begin or go into the reaction before it takes placeinto the reaction before it takes place

Chemical ReactionChemical Reaction

- when the chemicals that go into the - when the chemicals that go into the reaction change and new products reaction change and new products (chemicals) are formed.(chemicals) are formed.

Ex.Ex. MgIMgI22 ++ NaNa22OO NaINaI ++ MgOMgO

ReactantsReactants Products Products

When we write the compounds, we must When we write the compounds, we must make sure that they are balanced.make sure that they are balanced.

‘‘+’ – tells us that two compounds are +’ – tells us that two compounds are combining.combining.

Key Words – combines, mixes, Key Words – combines, mixes, reacts, and, etc.reacts, and, etc.

‘‘’ – ’ – acts as an equals sign to acts as an equals sign to separate reactants and products.separate reactants and products.

Key Words – to form, to produce, Key Words – to form, to produce, to make, synthesize, decompose, to make, synthesize, decompose, break down, etc.break down, etc.

Sample ProblemsSample Problems1) Magnesium bromide reacts with 1) Magnesium bromide reacts with

calcium nitride to form magnesium calcium nitride to form magnesium nitride and calcium bromide.nitride and calcium bromide.

2) Copper (II) oxide reacts with lithium 2) Copper (II) oxide reacts with lithium phosphide and produces copper (II) phosphide and produces copper (II) phosphide and lithium oxide.phosphide and lithium oxide.

3) Tin (IV) sulfide reacts with calcium iodide 3) Tin (IV) sulfide reacts with calcium iodide and makes tin (IV) iodide and calcium and makes tin (IV) iodide and calcium sulfide.sulfide.

4) Lithium chloride decomposed to form 4) Lithium chloride decomposed to form lithium and chlorine.lithium and chlorine.

Magic Seven – if ever the following elements are by Magic Seven – if ever the following elements are by themselves, they are found in pairs (diatomic).themselves, they are found in pairs (diatomic).

NN22, O, O22, F, F22, Cl, Cl22, Br, Br22, I, I22, At, At22, H, H22

5) Calcium reacts with iodine to form 5) Calcium reacts with iodine to form calcium iodide.calcium iodide.

6) Chromium (III) iodide combines with 6) Chromium (III) iodide combines with sodium phosphide to make sodium phosphide to make chromium (III) phosphide and sodium chromium (III) phosphide and sodium iodide.iodide.

H. Writing Word EquationsH. Writing Word Equations

ExamplesExamples

1) CaI1) CaI22 ++ AlAl22OO33 CaOCaO + AlI+ AlI33

2) CrI2) CrI22 ++ CuCu22S S CrS CrS + CuI+ CuI

3) Fe3) Fe22OO33 + KF + KF FeF FeF33 + K + K22O O

I. Acids and BasesI. Acids and Bases

AcidsAcids Have a sour tasteHave a sour taste Very corrosiveVery corrosive Neutralize basesNeutralize bases Conduct electricity very wellConduct electricity very well Dissolve in water to produce hydrogen Dissolve in water to produce hydrogen

ions (Hions (H++) in solution) in solution When an acid and a base neutralize each When an acid and a base neutralize each

other, they form salt and waterother, they form salt and water

NaOH + HCl NaOH + HCl H H22O + NaClO + NaCl Sodium Sodium HydrochloricHydrochloric Water Water Salt SaltHydroxideHydroxide Acid Acid

BasesBases Have a bitter tasteHave a bitter taste Very corrosiveVery corrosive Neutralize acidsNeutralize acids Conduct electricity very wellConduct electricity very well Dissolve in water to produce hydroxide Dissolve in water to produce hydroxide

ions (OHions (OH--) in solution) in solution When an acid and a base neutralize each When an acid and a base neutralize each

other, they form salt and waterother, they form salt and water

Acid-Base IndicatorsAcid-Base Indicators• Acid – Base indicators are substances that Acid – Base indicators are substances that

change different colors when added to acids change different colors when added to acids and bases.and bases.

• Litmus Paper Litmus Paper – red in an acid– red in an acid- blue in a base- blue in a base

• Bromothymol Blue – yellow in an acidBromothymol Blue – yellow in an acid- blue in a base- blue in a base

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

pH ScalepH Scale

An acid-base indicator will not tell you how An acid-base indicator will not tell you how acidic or basic a solution is. acidic or basic a solution is.

The pH scale indicates the level of acidity The pH scale indicates the level of acidity of a solution and it ranges from 0-14.of a solution and it ranges from 0-14.

pH of 0-6.9 is acidic.pH of 0-6.9 is acidic. pH of 7 is neutral.pH of 7 is neutral. pH of 7.1-14 is basic.pH of 7.1-14 is basic. The pH scale is logarithmic (based on the The pH scale is logarithmic (based on the

power of ten). This means the difference power of ten). This means the difference between a pH of 5 and 6 is actually ten between a pH of 5 and 6 is actually ten times. The difference between 4 and 6 is times. The difference between 4 and 6 is actually 100 times.actually 100 times.

Maintaining a constant pH is often very Maintaining a constant pH is often very important for biological systems.important for biological systems.

Human blood has a pH range of 7.35-7.45. Human blood has a pH range of 7.35-7.45. Any change from this could be fatal. Any change from this could be fatal.

Plants grow best in soil with a pH between Plants grow best in soil with a pH between 6 and 7. Any higher or lower, prevents the 6 and 7. Any higher or lower, prevents the plants from absorbing nutrients.plants from absorbing nutrients.

Shampoo normally has a pH of about 8. Shampoo normally has a pH of about 8. The human scalp has a pH of about 6. A The human scalp has a pH of about 6. A scalp that becomes too basic results in scalp that becomes too basic results in dandruff.dandruff.

THE ENDTHE END

Exam Time!