REVIEW - WHMIS: Workplace Hazardous Materials Information System

Safety in the Science Classroom: For each of the following rules, give one GOOD reason why we have that safety rule:

1) Never begin a lab or experiment without your teacher’s permission.

2) Keep your safety goggles on as long as there are any chemicals being used in the lab, even if you yourself are finished.

3) Never eat, drink or chew gum during a lab.

4) Make sure your hands are dry when you use electrical equipment.

5) Report any injuries, no matter how minor, to your teacher.

6) Do not mix chemicals unless directed to by your teacher or in your lab instructions.

7) If a chemical gets in your eye, flush it with running water for at least 15 minutes.

8) If your clothing catches fire, never run.

9) No goofing off during labs.

10)Never consume any items used in a lab.

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Topic 1 – Matter:

Particle Theory of Matter

1) All matter is made up of extremely tiny particles2) Each pure substance has its own kind of particle3) Particles attract each other4) Particles are always moving5) Particles at a higher temperature move faster than particles at a lower temperature

SOLID LIQUID GAS

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REVIEW:

- Homogeneous - Particles are uniformly scattered- Heterogeneous - Particles are not uniformly scattered- Suspension - Heterogeneous mixture made up of large particles that will settle if left undisturbed- Colloid- Heterogeneous mixtures made up of fine particles evenly distributed

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Topic 2 - Chemical/Physical Properties and Changes:

A property is a characteristic of something. - Physical Properties – A property that can be observed or measured without forming a new substance- Chemical Properties – A property that describes how a substance reacts with another substance.

Chemical PropertiesPhysical Properties

Qualitative Quantitativereacts with water colour melting temperature

reacts with air texture boiling temperaturereacts with acids taste density

stability smell viscositycombustibility state solubility

toxicity ductility conductivity

Physical Change - substance changes form but not chemical composition

Matter(Solids, Liquids,

Gases)

Mixtures

Hetergeneous (Mechanical

Mixtures)

Ordinary Mechanical

Mixtures

Suspensions

Colloids

Homogeneous (Solutions)

Pure Substances

Elements

Compounds

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Chemical Change - causes one or more new substances to be formed

If 2 or more of the following occur a chemical change has most likely occurred. 1) Heat is produced or absorbed2) The starting material is used up3) There is a change in colour4) A material with new properties forms5) Gas bubble form in a liquid6) A precipitate (solid) forms in a liquid 7) The change is difficult to reverse

Chemical Change Examples: Physical Change Examples:

Topic 3 – Atomic Theories:

What does the word “atom” mean?

Who proposed it?

When? Diagram and Description:

Dalton

Thompson

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Rutherford

Bohr

Modern Atomic Theory

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PARTS OF AN ATOM:

A:

B:

C:

D:

E:

Antoine Lavoisier (1743-1894)-> Came up with the Law of Conservation of Mass and the Law of Definite Composition

Law of Conservation of Mass: In a chemical change the total mass of the new substances is always the same as the total mass of the original substances

Law of Definite Composition: Compounds are pure substances that contain two or more elements combined together in fixed (or definite) proportions

Topic 4 - Elements & The Periodic Table:

The Story of Element Symbols

John Dalton developed a new set of symbols in the early 1800’s to improve communication between chemists. These symbols represented the elements that were known at the time.

Berzelius later revised Dalton’s symbols by replacing them with letters, instead of pictures. He represented the elements by their first letter (capitalized) or their first two letters (first one capitalized and the second letter lower case).

Elements were listed in order of their atomic mass.

Atomic mass is the mass of one atom of an element. It is represented in atomic mass units (amu).

Demitri Mendeleev later revised the pattern in 1869, when he organized the elements into the first periodic table.

Mendeleev Builds a Table

Mendeleev collected the 63 elements known at the

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time and arranged them according to their atomic mass - the average mass of an atom of an element - (which he wrote on a file card).

He then arranged the cards into a ‘solitaire-like’ table. He played with them, by sorting and arranging the elements in many different combinations. Mendeleev was able to identify gaps where elements, not yet discovered, would be able to fit.

Putting the Elements in Order

When Mendeleev arranged the elements in order of their mass he found that the properties of the elements repeated at periodic intervals. This enabled him to group elements into families. The gaps he left in the organization of the elements in his table were filled in many years later when more elements were discovered.

An element is defined by the number of protons it has. Carbon atoms have six protons, hydrogen atoms have one proton and oxygen atoms have eight protons. The chemical behavior of an element depends on the number of protons in an atom.

How to Read the Periodic Table

About 114 elements are known today. They are organized into what is called ‘The Periodic Table of Elements’.

* Horizontal rows are called periods (numbered 1-7)* Vertical columns form a group, or family of elements (numbered 1-18)

number of protons+ number of neutrons

= atomic mass number

So if you know the atomic number and mass number, you

can calculate the number of neutrons!

atomic mass number- atomic number

= number of neutrons

Practice:

1. Carbon has an atomic number of 6 and an atomic mass of 12. How many neutrons does it have?

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2. Fluorine has an atomic number of 9 and an atomic mass of 19. How many neutrons does it have?

3. If an atom of calcium has 21 neutrons, what is its atomic mass?

4. Lithium has an atomic mass of 7. How many protons and neutrons does it have?

Different Kinds of Elements

One way of classifying elements is to sort them into categories, based on their distinct properties.

Long before anyone knew any detail about the atoms or any of the periodic properties the elements were divided into two broad categories → metals and non-metals.

Metals Distinct properties of metals were malleability and ductility, shiny luster and were solid at room temperature (except mercury)

Non-Metals These fall into groups 14 to 16 in the periodic table. They can't conduct heat or electricity very well and are brittle. They also can't be made into wire or sheets. At room temperature, non-metals turn into gasses and solids.

Metalloids In-between elements were called ‘metalloids’, having properties of both metals and non-metals. These elements have both metal and non-metal properties. Some of them are semi-conductors, which means, they can carry an electrical charge under special conditions. Metalloids are great for computers and calculators.

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Chemical Families

A chemical family is a group of elements that share similar chemical and physical properties.

Family Name: Characteristics:

Alkali Metals These are group 1 in the periodic table. They don't occur freely

in nature and are softer than most metals. They are very

reactive and need special storage. They easily give off an

unpaired electron by forming a compound.

Alkaline Earth

Metals

These are group 2 in the periodic table. Because they're

reactive, they aren't found freely in nature. An example of an

alkaline earth metal is radium.

Halogens All 5 halogens are non-metallic elements. Compounds that

contain halogen are called ‘salts’. At room temperature, they

are in three states of matter: solid, liquid and gas.

The Noble Gases The 6 noble gases are in group 18. All of them have the

maximum number of electrons possible in their outer shell

which makes them stable. Examples of noble gases are helium,

neon and krypton. The noble gases are unique because they

are so unreactive.

Check Your Understanding:1. What is a metalloid?

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2. What is a chemical family?

3. What are the four chemical families that we’ve learned about so far?

4. What makes the noble gases unique?

5. What makes the alkali metals unique?

Topic 5 - Chemical Bonding:

Compounds vs. Elements: when we combine elements, we get

compounds. compounds are made up of DIFFERENT types of atoms. compounds have different properties than the elements that

they are made up of. in compounds, these elements are held together with a bond,

which is made from electrons.

Electron Configurations: Electrons are arranged in a certain way around the nucleus in

each element. There are electron shells that progress outwards from the nucleus. 2 electrons fit in the first shell, and 8 in the shells after that.

Ionic Bonds Molecular Bonds Forms between a metal and a non-

metal Occurs when atoms transfer

Forms between two non-metals. Occurs when atoms share electrons

with other atoms when they form a

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electrons to other atoms when they form a compound.

an ion is a charged atom (it has gained (-) or lost (+) an electron)

compound.(*also known as covalent bonding)

Ionic Bonds are stronger than Molecular BondsTherefore:

Ionic are usually solids, and molecular are usually liquids or gases, at room temperature.

The Language of Chemical Compounds:

All compounds have a chemical name and a chemical formula that follow international rules set by IUPAC, the International Union of Pure and Applied Chemistry. We can find one from the other! For example:

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Chemical Name: dihydrogen monoxide Chemical Formula: H2O

Chemical Name: sodium chloride Chemical Formula: NaCl

PRACTICE: How many atoms of each element exist in each molecule?

ATOM 1 ATOM 2 TOTAL ATOMSex: CH4 C = 1 H = 4 5CaCl2

AlCl3

N2O3

Formula Name for Chemical Compounds:

Ionic Compounds: Molecular Compounds:

1) Name of the metallic element comes first

2) Non-metallic element comes second. Change its ending to "ide

3) Put the names together.

ex. NaCl

sodium

chlorine changed to chloride

sodium chloride

1) Write the entire name of the first element

2) Change the ending of the second element to "ide"

3) Use a prefix to indicate the number of each atom in the formula. (LOOK BELOW)

4) Exception to the rule: We do not use ‘mono’ for the first element:

ex. CO2

carbon

oxygenchanged to oxide

1 = mono2 = dimonocarbon dioxide

carbon dioxide

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PRACTICE:

NaF

CaCl2

LiBr

MgS

KCl

PRACTICE:

IF

SO2

CH4

CS2

H2O

Name Formula for Chemical Compounds:

Ionic Compounds: Molecular Compounds:

1) List the symbol of the first element and the second element (remembering that it will be ending with an “ide”).

2) Look for the charge of each element, based on where it falls on the periodic table.From left, each column is 1+, then 2+, etc. From right, noble gases have no charge, then

ex. lithium oxide

Li O

Li –> 1+

O –> 2-

1) List the symbol of the first element. Then list the symbol of the second element (remembering that it will be ending with an “ide” and may have a prefix).

3) Look for the prefix in front of each element (mono, di, tri..). Remember that if there is only one of the first

ex. dihydrogen monoxide

H O

H -> di -> 2

O -> mono-> 1

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the halogens have 1-, etc.

3) Determine the number of atoms by the charge they have, remembering that the overall compound must be neutral. Use the crisscross rule to help you. Write the correct formula.

Li2O

element that there will not be a mono in front.

4) Put the number associated with each prefix by the bottom right hand corner of each element.

H2O

Crisscross Rule:

PRACTICE:

lithium bromide:

calcium sulphide:

aluminum oxide:

magnesium chloride:

calcium sulphide:

PRACTICE:

carbon tetrafluoride:

diphosphorus trioxide:

sulphur dihydride:

nitrogen trichloride:

dinitrogen trioxide:

Topic 6 - Chemical Reactions:

A chemical reaction takes place when two or more substances combine to form new substances. The starting materials are called reactants. The new materials produced by the reaction are called products. The properties of the products differ from those of the reactants, thus a chemical change has occurred. A chemical change results from a chemical reaction.

- A chemical reaction, which releases energy, is called EXOTHERMIC. - A chemical reaction, which absorbs energy, is called ENDOTHERMIC.

Chemical Equations

Chemical reactions can be written as word equations and chemical equations.

The word equation gives the names of all the reactants followed by an arrow that points to the names of all the products. We use a ‘+’ sign to separate the different reactants and products.

silver + bromine silver bromide

(REACTANTS) (PRODUCTS)

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The chemical equation substitutes the chemical formulas for the chemical names.

Ag + Br AgBr

Chemists usually put symbols in brackets after the reactants and products to indicate states of matter (s = solid, l = liquid, g = gas)

Ag(s) + Br(l) AgBr(s)

Fill in the table using IUPAC naming rules and the information shown above about formulas. Use symbols to indicate states of matter.

word equation: chemical equation:

magnesium + oxygen magnesium oxide

Li(s) + NaCl(s) LiCl(s) + Na(s)

carbon + oxygen carbon monoxide

C3H8(l) + O2(g) CO2(g) + H2O(l)

dihydrogen dioxide dihydrogen monoxide + oxygen

iron + oxygen iron oxide

Topic 7 - Reaction Rate:

The speed of a chemical reaction is called the reaction rate. Reaction rate is affected by four factors:

• Temperature of the reactants affects the rate of all reactions (The higher the temperature the faster the reaction rate)

• Surface Area of the reactants affects the reaction rate (The more surface in contact, the faster the reaction rate)

• Concentration of the reactants affects the reaction rate. (The higher the concentration, the faster the reaction rate)

• The presence of a Catalyst affects the reaction rate

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Catalysts – Speeding up a Reaction: A catalyst is a substance that helps a reaction proceed faster, and is not consumed in the reaction. Enzymes are natural catalysts that help in the reactions in the body, which break down food.

Inhibitors – Slowing down a Reaction: Inhibitors are substances that slow down chemical reactions. Inhibitors are added to foods to slow down their decomposition.

Corrosion: Corrosion is a slow chemical change that occurs when oxygen in the air reacts with a metal. Corrosion is a chemical reaction in which the metal is decomposed (eaten away), when it reacts with other substances in the environment. The corrosion of iron is called 'rusting'. Preventing Corrosion: Corrosion protection (e.g. painting the metal) involves protecting metal from contact with the environment and the factors that affect the reaction rate of this chemical reaction. Coating a corrosive metal with a thin layer of zinc is called galvanization.

Combustion: Combustion is the highly exothermic combination of a substance with oxygen. Combustion requires heat, oxygen, and fuel. Products: The products of combustion are not always beneficial. Burning fossil fuels (such as propane) produces carbon monoxide, carbon dioxide, sulfur oxides, nitrogen oxides, smoke, soot, ash and heat. Some of these products are pollutants.

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