Science 10 Review - Chemistry

What is chemistry? the study of changes in matter

Classifying matter

matter: anything that has mass and occupies space. heterogeneous substances: non-uniform and may consist of more than one phase (e.g.

Coca-Cola, ice cream float) homogeneous substances: uniform and consist of only one phase (e.g. tap water)

homogeneous mixtures (solutions) can be separated by physical means such as filtering (e.g. Kool-aid)

pure substances can’t be separated by physical means (e.g. water) compounds can be separated by means of a chemical change into its

different atoms (e.g. water can be separated into hydrogen and oxygen) elements cannot be broken down into simpler chemical substances

The periodic table based on rules

established by IUPAC (International Union of Pure and Applied Chemistry), elements are displayed in a chart called the periodic table

the characteristics of the elements listed on the

Matter

Heterogeneous (Non-uniform mixtures)

Homogeneous(Uniform matter)

Pure substancesHomogeneous mixtures

(Solutions)

Compounds Elements

periodic table are accurate at SATP (standard ambient temperature (25°C) and pressure (100kPa))

Split into three categories: Metals, non-metal and metalloids Each one of these groups contains elements with similar chemical and

physical properties.

features of the modern periodic table: family / group

vertical column with similar chemical properties alkali metals: (1) soft, silver-coloured, react violently with water to form basic

solutions alkaline-earth metals: (2) light, reactive metals that form oxide coatings

when exposed to air transition elements: exhibit a wide range of chemical and physical properties halogens: (17) extremely reactive non-metals noble gases: (18) extremely low chemical reactivity

period horizontal row of elements whose properties gradually change from metallic

to nonmetallic as you move from left to right

metals / non-metals Metals Metals makeup more than 75% of the elements on the periodic table. Metals are characterized by the following physical properties.

1. They are shiny ( have a high luster).2. They are usually solids at room temperature.3. They are malleable ( can be hammered, pounded, or pressed into different shapes without breaking). 4. They are ductile (can be drawn into thin sheets or wires without

breaking). 5. They are good conductors of heat and electricity

Metals can be both reactive or inert o Reactive: such as sodium, which will combust into a flurry of flame

when it come on contact with air.o Inert: extremely un-reative, like platinum or gold

Non-metals There are 17 nonmetals in the periodic table, In general, they can be grouped together b/c they DO NOT

resemble metal more than having a relationship to each other. They can be a variety of states, (although they are usually

gases at room temperature). They do not have a luster. They are poor conductors of heat and electricity. They generally exist as molecules.

Metalloids The metalloids are B, Si, Ge, As, Sb, Te, Po and At.

The members of this group are the least uniform in character. The metalloids are NOT as good at conducting as the metals, but they are

better conductors than the nonmetals. Many of them are known as semiconductors.

Info on the periodic table Every element on the periodic table is in it’s own box. Each box has the same information in it.

atomic number (= number of protons)atomic mass (mass of one mole of that substance. 1 mole = 6.02 x 1023

molecules)Symbol/ Namecommon/other ion charge (how many electrons gained/lost by atoms to form ions

Atomic Theory atoms:

based on these laws, John Dalton introduced a new atomic theory of matter in 1803. all matter is composed of tiny, indivisible particles called atoms all atoms of the same element have identical properties, while atoms of different

elements have different properties atoms of two or more elements can combine in constant ratios to form new

substances electrons:

discovered in the late 1800s by J.J. Thompson tiny, negatively charged particles called electrons could be separated from

atoms; that is, that atoms could be further divided into smaller particles. the net charge of the atoms was zero (neutral)

nucleus & protons: shortly thereafter, Ernest Rutherford revised the previous models:

atoms contain a tiny, positively-charged core called the nucleus, which is surrounded by mostly empty space containing negative electrons. Though tiny, the nucleus makes up most of the mass of the atom.

the nucleus is made up of tiny particles called protons. Each element has a different number of protons ( its atomic number).

later, another scientist also found the nucleus contained equally small, but neutral, particles called neutrons

electrons & orbitals: Niels Bohr discovered that electrons occupy fixed orbits, like planets orbiting around

the sun. electrons cannot exist between levels, but they can move from one level to

another. each level has a fixed capacity for electrons

the shell closest to the nucleus can only hold 2 electrons, the second and third can both hold 8 if a shell is full, new electrons cannot move to that shell

each shell represents an amount of energy held by that electron electrons further from the nucleus have more energy than those in the

closest orbit. an element with its outermost orbit full is stable and unreactive

particle

symbol

charge

mass notes location

proton p+ 1+ 1.7 x 10-24-g

make up nearly all the mass of an atom, but hardly any volume

in the nucleus

neutron n 0 1.7 x 10-24-g

electron

e- 1- 9.1x10-28g barely any mass, but most of the volume

around the nucleus

Summary of what we know about the atom Every element is made of up of three subatomic components.

Protons Neutron Electrons

Protons and neutrons are in the nucleus in the middle of the element. Electrons orbit the outside. These electrons are drawn to the

nucleus because of their opposite charges

Atomic mass vs. Mass number Atomic mass is the mass of the whole element. You add together ALL of its components:

protons + neutrons + electrons = atomic mass

This gives you a number with digits in to the 10,000th place!

Isotopes Def: Atoms with differing weights but are the same type of

elements. ex carbon-12 and carbon-14). Remember: atoms always have the same number of protons.

Number of Protons NEVER changes!!! Therefore isotopes have differing numbers of neutrons.

To make it simpler we use Mass Number. protons + neutrons = mass number Therefore…

mass number – protons = neutrons

Ex. a) vandium-51mass number – protons = neutrons51 – 23 = 28There are 28 neutrons & 23 protons in vandium.

Try: nickel-58, bromine-79, argon-40, uranium-238

Ions and the Octet rule The octet rule says that atoms tend to gain, lose or share electrons so as to have

eight electrons in their outer electron shell. Ex: the halogens--each chlorine is missing only one electron in their valence orbital,

so they each share a valance electron from each other so the molecules to stabilize. This is why all the halogens are diatomic!

Other elements do the same thing.

In the case of water Oxygen needs two electrons (to move

from 6 to 8 valance electrons) Each hydrogen has one too many. Each hydrogen gives an electron to the oxygen; oxygen now has a full

valance orbital The oxygen shares the electrons with hydrogen too, so it has a full orbital

too.

Formation of ions~ Ultimately, elements are lazy! Elements will do whatever is the easiest way to get

a full valance orbital. ~ There are two types of ions:

Cations: give up (lose) electrons. Since they now have more protons than electrons, they have a positive charge.

Sodium has 11 protons and 11 electron; only one electron in its valance orbital, (it is much easier for it to lose one than find seven....)

This leaves it with 11 protons and only 10 electrons…thus it now has a charge of 1+

b/c there is one more proton than electron.

~ Anions: pick up (gain) electrons. Since they now have more electrons than protons, they have a negative charge.

Chlorine has 17 protons and 17 electrons; it has seven electron in its valance orbital

(it is much easier for it to gain one than find seven)

This leaves it with 17 protons and 18 electrons…thus it now has a charge of 1-, because there is one more electrons than proton.

Lets try some! What would the following elements be as ions?Magnesium, nitrogen, selenium, iodine, potassium & oxygen

Bohr Diagrams ~ Bohr Diagrams are used to diagrammatically represent elements and ions. ~ They show the number of protons, neutrons and electrons. ~ The number of electron orbitals is equal to the number of the row the element is in.~ The number of electrons that can fill each orbital is equal to the number of elements in each row.~ The number of valance electrons is equal to the number of the column that the element is in.

To draw a Bohr Diagram~ Place a circle in the center to represent the nucleus.~ Write the symbol to represent the element in the circle. ~ Write the number of protons & neutrons in the circle to.~ Draw in the correct number of orbital

Recall the number of rings = column the element is in

The electrons are placed on the rings

Recall The number of electrons that can fill each orbital is equal to the number of elements in each row AND The number of valance electrons is equal to the number of the column that the element is in.

Types of compound’s~ Ionic:

cmpds that have one metal and one non-metal ion (one positive and one negative)

Ex. Na+ & Cl- make NaCl(s)

~ Molecular: cmpds that have two non-metal ions Ex. C & O make CO2 (g)

Ionic Cmpds~ Are a result of ionic bonds~ Naming: the metal is always first, the non-metal second. The non-metals

name is changed to have an “ide” ending (ie. sodium chloride)

~ Ionic bonds form between metals and non-metals,

This means that there is a tight arrangement of particles in rigid pattern, which is hard to break down, giving them a high melting/ boiling temp.

Conduct electricity (electrolytes) Solid at room temp

~ In ionic bonding, valence electrons are completely transferred from one atom to another. 

~ The result? Ions! Electrically charged atoms. Cations are positively charged (Mg 2+, H+, Na+) Anions are negatively charged (O2-, Cl-)

~ The oppositely charged ions are attracted to each other by electrostatic forces.

How to write Ionic Cmpds:~ Step 1: Write each ion with its charge

Remember: Certain columns on the periodic table are always the same, and some have more than one choice.

Ex. calcium and bromine: Ca2+ and Br –

~ Step 2: Figure out how many of each you need to make the charges balance.

The best way is to do a switch-er-oo between the number of atoms and the opposite ion’s charge.

~ Step 3: Write the formula using subscripts to show how many of each atom you need AND the state

CaBr2 (s)

Note: Ionic compounds are always solid (s)

Multiple charges…~ These are called multivalent ions.~ In order to know which of the ion charges you need the formula will have a roman numeral in it.

Cr2+ is written chromium (II) Co3+ is written cobalt (III)

Polyatomic Ions~ These are the ions found middle area of the periodic table~ Elements that are already grouped together and poses a charge.

Molecular Cmpds~ Unlike ionic compounds; a positively charged metal ion and a negatively charges non-metal ion, molecular compounds are a combination of two non- metals . ~ Since both are negatively charged, we can not balance the formula to equal zero.

Covalent bonds~ Covalent bonds are formed as a result of the sharing of one or more pairs of bonding electrons; (this is what hold molecular compounds together)~ Each atom donates half of the electrons to be shared.

Where the clouds overlap they are thicker, and their electric charge is stronger.

~ Do not have a tight crystal structure so the melting/ boiling point is lower.~ Do not conduct electricity (non-electrolyte)~ Can be any state at room temp.

Naming: ~ The first element in the compound uses the element name. The second element in the compound has the suffix ide added to it- just like ionic compounds HOWEVER…~ When there is more than one of the atom in the formula, a prefix is used to specify how many of that element there is.

mono- 1 hexa- 6di- 2 hepta-7tri- 3 octa-8tetra- 4 nona-9

penta- 5 deca-10~ Here comes the exception…when the first element has only one, no prefix is used. If the second element has only one, the prefix mono is attached.

Acids:~ Ionic cmpds, where the metal is always hydrogen.~ In solution will have a pH lower than 7~ React predictably with indicators like litmus paper

Bases:~ Ionic cmpds, where the non-metal is always hydroxide (OH - ). ~ In solution will have a pH higher than 7~ React predictably with indicators like litmus paper

Naming Acids~ If the compound name ends in “ide” the name of the acid becomes hydro--ic acid.

For example HCl, hydrogen chloride, become hydrochloric acid ~ If the compound name ends in “ate” the name of the acid becomes --ic acid.

For example H2SO4, hydrogen sulfate, become sulfuric acid ~ If the compound name ends in “ite” the name of the acid becomes --ous acid.

For example HClO3, hydrogen perchlorite, become perchlorous acid ~ In general the H + ion always goes first …unless the acid has an “organic group”; (a molecule containing COOH), then the H+ goes last. ~ Acids are always written with an (aq) subscript.

Let’s try some!RULE 1: hydrogen ---ide becomes hydro ---ic acid

HF(aq)

H2P(aq)

HI (aq)

RULE 2: hydrogen ---ate becomes ---ic acidHClO3(aq)

H3BO3(aq)

HNO3(aq)

RULE 3: hydrogen ---ite becomes ---ous acidHNO2(aq)

H2ClO2(aq)

H2SO3 (aq)

Solubility: ~ the property of a solid,

liquid, or gaseous chemical substance called solute to dissolve in a liquid solvent to form a homogeneous solution .

~ The solubility of a substance depends on the specific solvent as

well as the temperature and pressure~ To predict the solubility of ionic

compounds only we use a solubility table.

~ The most up-to-date version of the solubility table is on page two of your data-booklet.~ Things that are “soluble” will dissolve and form a solution. ~ Things that are “slightly soluble” will NOT dissolve but form a precipitate (chunks that float viable within the water)

Lets Practice!Li2SO4, CaSO4, NH4F, LiF, Rb2O, Cs3As,

AgCl

Chemical Rxns~ There are 5 types of Chemical reactions:

~ Formation: creating a compound from two elements element + element → compound Na(s) + Cl(g) →NaCl(s)

~ Simple decomposition: this is when a compounds breaks into its components compound → element + element/polyatomic ion H2SO4(aq) → H+ (aq) + SO4 2-(aq)

~ Single replacement: (one element replaces an element in the compound to make a new element/compound combo)

element + compound → new element + new compound H2SO4 (aq) Zn(s) → H2(g) + ZnSO4(s)

~ Double replacement: (all the ions switch partners) compound + compound→ new compound + new compound HCl(aq) + NaOH(aq) → NaCl(s) + HOH(aq)

~ Combustion: (the burning of a hydrocarbon in the presence of O2) hydrocarbon + O2 → CO2 + H2O C6H12(g) + O2(g) → CO2(g) + H2O(l)

Rules:1. In all chemical reactions: atoms, mass and energy are conserved

(There is the same amount of each on either side of the arrow)

2. Balance the chemical reaction by:a. Write the correct chemical formulas for the reactants and productsb. Identify all the atoms on the reactant side and identify all the similar atoms

on the product side.c. Compare the numbers of atoms on each side and try to balance them by

adding coefficients on each side.

Lets Practice!Na (s) + Br2 (l)→ Mg (s) + F2 (g) →

Calcium and oxygen produces? Magnesium phosphide →

Fe(s) + Cu(NO3)2(aq) → Zinc and iron (II) chloride →

CaO(s) → C6H12O6(s) + O2(g) →

Copper (II) nitrate + potassium bromide →

Molar Mass~ To calculate the molar mass of a compound, add the individual atomic molar masses of all the atoms in the compound together.

Let’s Practice!~ Calculate the molar masses of the following compounds:

Water:

Glucose (C6H12O6):

Molar Mass Calculations

~ Manipulate the formula to solve for mass

~ How many moles are in 88.02g of carbon dioxide?

~ What is the mass of 4.38 moles of carbon dioxide?

Physics Review

What is Physics? The branch of science concerned with the nature and properties of matter

and energy.

Thermodynamics The First law of thermodynamics a re-

statement of the Law of Conservation of Energy

Energy cannot be created or destroyed; it can only be converted from one form to another

EXCEPT in the Law of Thermo-dynamics one of the forms of energy is always heat.

Second Law of Thermodynamics piggy- backs on the 1st Law agreeing that the quantity of energy remains the same in a system…

HOWEVER the usable quality of the energy deteriorates over time.

Each time energy is converted from one form to another, some of the useful energy is always “lost” (reduced to a lower-quality, less useful form).

The 2nd Law expresses reality: no system can convert energy from one form to another with 100% efficiency.

Most often, this “lost” less useful energy in the form of thermal energy; heat as a result of friction and movement within the system.

The amount of “useful output” relative to the amount of energy input is referred to as the machines efficiency.

Can be found using the formula:

Rearrange the formula for percent efficiency to solve for:~ total work output ~ total work input

Lets Practice!

A Bunsen burner supplies 4.00 x 103 J of heat to a small beaker of water. Only 125 J of heat is gained by the beaker and water. Calculate the percent efficiency of the burner.

total work outputpercent efficiency = 100%total work input

A small electric motor has an efficiency of 85%. In lifting a small load, it produces 15 J of mechanical energy input. Calculate the useful mechanical energy output of the motor.

Systems Recall the three different conditions that energy transfers can occur in:

Open system: a system that exchanges matter as well as energy with the surroundings.

Closed system: A system that can exchange energy but NOT matter with its surroundings.

Isolated system: A system that can exchange neither energy nor matter with its surroundings. Truly isolated physical systems do not exist in reality.

Significant Figures/ Digits The number of significant digits in an answer to a calculation will depend on the

number of significant digits in the given data:

When are Digits Significant? Non-zero digits are always significant.

22 has two significant digits (2 and 2). 22.3 has three significant digits (2, 2 and 3).

With zeroes, the situation is more complicated: Zeroes placed before other digits are

not significant; 0.046 has two significant digits

(4 and 6, b/c the preceding zeros DO NOT count).

Zeroes placed between other digits are always significant ; 4009 kg has four significant digits (4, 0,0 and 9).

Zeroes placed after other digits but behind a decimal point are significant ; 7.90 has three significant digits (7, 9 and 0).

Why? Values to the right of a decimal place can be rounded as necessary, values to the

left of a decimal CAN NOT.

So that we can round appropriately to give an answer with the correct number of digits, scientific notation is used.

If the answer comes to 8219.10 8.219 x 103 has four significant digits 8.22 x 103 has three significant digits. 8.2 x 103 has two significant digits

Sig Dig’s for Multiplication & Division Functions The number of significant digits in an answer should equal the least number of

significant digits in any one of the numbers in the question Ex. What is the speed of a jet plane that travels 528 meters in 4.0

seconds? v = ∆d ∆tv = 528m

4.0 s v = 132v = 1.3 x 10 2 m/s

Sig Dig’s for Addition & Subtraction When adding and subtracting, your answer must have the same number of

decimals places as the least number of decimal places (not total number of digits) in the in the question

Ex: 5.67 J 1.1 J + 0.9378 J 7.7078

* Your answer can have only one decimal place* Ans = 7.7 J

Intermediate Answers ALWAYS Keep AT LEAST One Extra Digit in Intermediate Answers

When doing multi-step calculations, keep at least one more significant digit in intermediate results than needed in your final answer.

If the final answer requires two significant digits, carry at least three significant digits in calculations (or just keep them in your calculator). Scalar Vector

◦To posses only magnitude, (numerical value only)◦Ex. It is 10 meters to the neighbors.

◦To have both magnitude, (numerical value) AND direction. ◦A vector symbol (v ) is used above the value. ◦Ex. It is 10 meters EAST to the neighbors.

Distance Displacement◦The amount of space between two things.◦Ex. It is 389 km from Edmonton to Jasper

◦The amount of space between two things IN A GIVEN DIRECTION.◦Ex. It is 389 km[West] from Edmonton to Jasper

Speed Velocity◦The rate of travel.◦Ex. We travelled at 110km/h to get from Edmonton to Jasper.

◦The rate of travel IN A GIVEN DIRECTION.◦Ex. We travelled at 110km/h [West] to get from Edmonton to Jasper

Time Acceleration◦The method of measuring the passage of time.◦Ex. Science class is 60 min long.◦Ex. It takes 3 ½ hours to get to Jasper

◦The act of increasing in speed (or velocity) over a period of time. ◦Ex. You accelerate from 60km/h to 100km/h to merge onto the highway

*528 has 3 sig digs (5, 2 and 8), 4.0 has two (4 and the trailing 0). So your answer can have only 2 digits *

* 5.67 J has two decimal places, 1.1 J has one decimal place, 0.9378 J has four decimal places

Formula Manipulation Rearrange the formula to solve for:

Δd ~ Δt

~ Δv ~ Δt

~ vf ~ vi

~ Δt ~ vi

~ vf

~ vi ~ a

What is Biology? The branch of science concerned with the science of living matter in all its forms

especially with reference to origin, growth, reproduction, structure, and behavior.

Biosphere Earth's zone of air, soil, and water that is capable of supporting life, traditionally

thought of as a zone reaching about 10 km into the atmosphere and down to the deepest ocean floor.

Biomes A biome is a large geographical region

with a specific climate that the plants and animals that inhabit it are adapted to.

Cells and biomes are open systems that exchange matter and energy with their surroundings.

Biomes can be broken down into specific ecosystems.

a system formed by the interaction of a community of organisms with their environment.

The solid outer layer of the Earth; includes both land area and the crust beneath the oceans and other water bodies.

The part of the Earth composed of water including clouds, oceans, seas, ice caps, glaciers, lakes, rivers, underground water supplies, and atmospheric water vapor.

The envelope of gases surrounding the Earth

Ecosystems consist of biotic & biotic factorsBiotic Factors Abiotic factors

living organisms in the environment physical, non-living parts of the environment

examples: animals plants

~ examples: water supply light soil quality climate / temperature

Life Processes’Animals Plants

Must eat other things in order to meet their nutrition needs.

Some animals eat only plants (herbivores)

Some animals eat other animals (carnivores)

Some eat both (omnivores)

Plant can produce their own food from the sun.

When animals ingest nutrients it must first be broken down physically (by chewing and digesting) and chemically (by the acids/ enzymes) in the stomach and digestive tract.

Instead of ingesting nutrients, plants are able to combine elements in it’s environment to produce food.

Cellular Respiration PhotosynthesisOnce food has been broken down into small enough particles, it is taken into the blood and distributed to each cell.

At the cellular level digestion is referred to as cellular respiration

The process of converting light energy to chemical energy and storing it in the bonds of sugar.

Plants only need light energy, CO2, and H2O to make sugar.

The series of reactions and processes that take place in the cells of organisms to convert food into energy (ATP)

The process of photosynthesis takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis.

Cellular respiration is a process that requires oxygen and nutrients and gives off carbon dioxide and water and energy for the organism.

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy 6CO2 + 6H2O + light energy → C6H12O6 + 6O2