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In this chapter we are going to look at the motion of objects that are either projected, thrown, or shot directly into the air, be it vertically upwards, downwards or when objects are dropped

This is something that everyone has experienced while playing games and we all have a strong intuition that 'what goes up, must come down', but now we'll study why that is the case.Video: 27JYUnits and unit conversions - Physical Sciences, Grade 10, Science skillsRectilinear motion - Physical Sciences, Grade 10, Motion in one dimensionLinear equations - Mathematics, Grade 10, Equations and inequalitiesQuadratic equations - Mathematics, Grade 10, FunctionsUnderstand the principle of free falling under gravity with a constant acceleration for an upwards and downwards motion.Know that it's only vertical displacement no horizontal displacement.Always move only under the influence of only gravity.The meaning of time symmetry and the magnitude of velocity.Do an experiment to measure the position and time during a motion.Calculations done on projectiles by knowing how to use a single set of equations.Graphical representations of the equations of motion - Draw graphs for the projectiles motions.Deduct equations and determine the position, displacement, velocity or acceleration from the graphs.Describe the motion of the object from the graphs.Units and unit conversions - Physical Sciences, Grade 10, Science skillsRectilinear motion - Physical Sciences, Grade 10, Motion in one dimensionLinear equations - Mathematics, Grade 10, Equations and inequalitiesQuadratic equations - Mathematics, Grade 10, Functions

This section studies simple organic molecules, functional groups and the physical properties associated with these functional groups

Only molecules with one type of functional group, and no more than three of the same functional group, should be studied

This section is a basis for any organic chemistry they may study beyond school so it is important that learners have a thorough understanding of this chapter

Some common polymers are also covered in this chapter, learners should understand the environmental impacts of these polymers as well as their connection with simple organic molecules through the monomers they are formed from.This section of work is the first chemistry chapter of the Grade 12 year

Learners should have an understanding of intermolecular forces and chemical bonds from Grade 11

If possible more time could be given here to ensure a thorough understanding, as there is a lot of work to cover.Emphasis should be placed on the different representations of organic compounds: macroscopic, sub-microscopic, symbolic representations and the links between all three

Where possible, use atomic model kits to help explain reactions, physical properties and the structure of molecules.The following topics are covered in this chapter

What makes a molecule organic, and organic molecular structures This chapter starts with a brief introduction to what makes a molecule organic (containing carbon atoms)

This then leads in to the properties of carbon that make it so unique

Learners are introduced to structural, semi-structural, condensed and molecular formula representations for molecules

It is important that they have a thorough understanding of this before moving on as they will use these representations throughout the chapter

It is also important that learners understand that molecules are not two-dimensional, if possible do some demonstrations with atomic model kits so they can get a better feel for the shape of an organic molecule

Semi-structural representations are not required by CAPS, but will be shown in many textbooks and so it would be good for the student to understand them

Functional groups Understanding functional groups is essential to understanding organic molecules

An introduction to each of the required basic functional groups, the homologous series to which they belong, and their general formulas are covered in this section: hydrocarbons (alkanes, alkenes, alkynes), alcohols, alkyl halides (specifically haloalkanes), aldehydes, ketones, carboxylic acids and esters

The concept of saturated and unsaturated compounds is also covered, this will become more important later in the chapter when studying reactions

Isomers of compounds with the same functional groups, and compounds with different functional groups are also covered

IUPAC naming A good knowledge of IUPAC naming is very important in organic chemistry

This section walks the learners through the naming of the functional groups, with many worked examples

Going through those worked examples and the associated exercises will help the learners understand this section

There are a number of in-class activities provided that will also help with understanding

The naming of compounds with more than three of the same functional group, or more than one functional group, is not required by CAPS

Chain lengths of no more than eight carbon atoms are allowed, and esters may not have branched groups

Physical propeties and structure A revision of Grade 11 intermolecular forces would be useful before starting this section

The important IMF this year are hydrogen bonds and van der Waals forces

The physical properties covered include: viscosity, density, melting and boiling points, flammability and vapour pressure, volatility, physical state, smell

It would be good for learners to revise molecular shape from Grade 11 as well

The changes in physical properties are linked to the intermolecular forces of the molecule, which is in turn linked to functional groups, chain length and chain branching

Although these are seperated into sections the learner should understand that they are linked (different intermolecular forces are due to functional groups, chain length, etc.)

Applications of organic chemistry In this section learners will explore the applications of organic molecules

Specifically the cracking of hydrocarbons, and the (complete) combustion of alkanes

Esters are also covered in more detail in this section, with industrial uses

Addition, elimination and substitution reactions The learners need to know the addition, elimination and substitution reactions mentioned in this section, including reaction conditions and the major and minor products that will be formed

They should understand the difference between an addition reaction, an elimination reaction and a substitution reaction and the reactants required in each specific reaction

Plastics and polymers The polymers covered in this section are: polyethene, polypropene, polyvinyl chloride, polyvinyl acetate, polystyrene, polyethylene terephthalate and polylactic acid

Learners should understand what makes a compound a polymer, the difference between an addition and a condensation reaction, and how to determine the polymer from the monomer and the monomer from the polymer

The learners will be using dangerous chemicals and should be properly instructed on the correct use of safety equipment, including safety goggles, gloves and protective clothing

They should also be reminded not to sniff any chemicals as the fumes can be dangerous as well

More information on laboratory procedures as well as safety precautions is provided in Chapter 1 (Science skills).These experiments are also an excellent opportunity to get the learners to research organic molecules

Before any experiment the hazards of the chemicals being worked with should be studied

Have the learners do the research for at least some of the experiments before completing them as a way of better understanding the molecules.Do not confuse organic compounds with naturally produced food

Organic compounds are often produced in a laboratory.Organic chemistry is the branch of chemistry that deals with organic molecules

An organic molecule is one which contains carbon, although not all compounds that contain carbon are organic molecules

Noticeable exceptions are carbon monoxide (), carbon dioxide (), carbonates (eg calcium carbonate), carbides (eg calcium carbide) and cyanides (eg sodium cyanide)

Pure carbon compounds such as diamond and graphite are also not organic compounds

Organic molecules can range in size from simple molecules to complex structures containing thousands of atoms!Although carbon is present in all organic compounds, other elements such as hydrogen , oxygen , nitrogen , sulfur and phosphorus are also common in these molecules.Organic moleculeAn organic molecule is a molecule that contains carbon atoms (generally bonded to other carbon atoms as well as hydrogen atoms).Organic compounds are very important in daily life and they range from simple to extremely complex (Figure 4.1)

Organic molecules make up a big part of our own bodies, they are in the food we eat and in the clothes we wear

Organic compounds are also used to make products such as medicines, plastics, washing powders, dyes, along with a long list of other items

There are millions organic compounds found in nature, as well as millions of synthetic (man-made) organic compounds.

We use the term `work' in everyday conversation to mean many different things.We talk about going to work, doing homework, working in class.Physicists mean something very specific when they talk about work.In Physics we use the term work to describe the process of transferring energy from object or system to another or converting energy from one form to another.You will learn that work and energy are closely related to Newton's laws of motion

You shall see that the energy of an object is its capacity to do work and doing work is the process of transferring energy from one object or form to another by means of a force

In other words, an object with lots of energy can do lots of work

when object A transfers energy to object B, the energy of object A decreases by the same amount as the energy of object B increases, we say that object A does work on object B

Lifting objects or throwing them requires that you do work on them

Even making an electrical current flow requires that something do work

Objects or systems must have energy to be able to do work on other objects or systems by transferring some of their energy.Units and unit conversions, Physical Sciences, Grade 10, Science skillsEquations - Mathematics, Grade 10, Equations and inequalitiesTechniques of vector addition - Physical Sciences, Grade 10, Vectors and scalarsNewton's laws - Physical Sciences, Grade 11, ForcesForce diagrams - Physical Sciences, Grade 11, ForcesVideo: 27RGWork:Define word done on an object by a force.Understand that work is a scalar.Calculations done on the net work done on an object.Understand the difference of positive, negative and no work done.Drawing of force diagrams to determine the net work done on an object - Ignore perpendicular forces.Work-energy theorem:Know the difference between conservative and non-conservative forces.Understand the result of a net force working in on an object.Application of the work-energy theorem to objects on horizontal and inclined planes.Calculations of different motions of objects.Conservation of energy:Definition of conservative and non-conservative forces and examples.Know the relationship between conservative and non-conservative forces and mechanical energy.Calculations done on the conservation of energy.Using calculations to prove the relationship between non-conservative forces and mechanical energy.Power:Definition of power as the rate at which work is done.Calculations done when work is done.Understand what is needed to keep an object moving at a constant speed.Calculations done when an object moves at a constant speed.Calculations done on power.Calculations done on maximum and minimum power.Units and unit conversions, Physical Sciences, Grade 10, Science skillsEquations - Mathematics, Grade 10, Equations and inequalitiesTechniques of vector addition - Physical Sciences, Grade 10, Vectors and scalarsNewton's laws - Physical Sciences, Grade 11, ForcesForce diagrams - Physical Sciences, Grade 11, Forces

Have you noticed how the pitch of a police car or ambulance siren changes as it passes where you are standing, or how an approaching car or train sounds different to when it is tavelling away from you

If you haven't, try to do an experiment by paying extra careful attention the next time it happens to see if you can notice a difference in pitch

This doesn't apply to just vehicles and trains but anything that emits waves, be those sound waves or any other electromagnetic (EM) waves.The effect actually occurs if you move towards or away from the source of the sound as well

This effect is known as the Doppler effect and will be studied in this chapter.The Doppler effect is named after Johann Christian Andreas Doppler (29 November 1803 - 17 March 1853), an Austrian mathematician and physicist who first explained the phenomenon in 1842.Video: 27SRUnits and unit conversions - Physical Sciences, Grade 10, Science skillsEquations, Mathematics - Grade 10, Equations and inequalitiesSound waves - Physical Sciences, Grade 10, SoundElectromagnetic radiation - Physical Sciences, Grade 10, Electromagnetic radiationThe Doppler Effect with sound:Definition of the Doppler Effect with examples.Explanation to what happens with sound when objects move relative to each other.Calculations done to determine the frequency when one of the two objects are moving.Description of applications with ultra sound waves.THE Doppler Effect with light:Understand the relationship between light and the Doppler Effect.Application of the Doppler Effect and light concerning the universe.Units and unit conversions - Physical Sciences, Grade 10, Science skillsEquations - Mathematics, Grade 10, Equations and inequalitiesSound waves - Physical Sciences, Grade 10, SoundElectromagnetic radiation - Physical Sciences, Grade 10, Electromagnetic radiation

A car slowly rusting away, a match burning, a tablet dissolving in water

All of these are chemical reactions and all of these take place at different rates

If you were to hold a race between these three reactions you would find that the match wins (it burns quickly), while the car rusting would lose (it may take years to rust).In this chapter we will look at why reactions proceed at different rates (speeds) and how we can change the rate of the reaction.In physics, speed is the scalar measurement that tells us how fast or slow an object is moving (position vs

For reactions the speed (or rate) of a reaction means how fast or slow the reaction is and indicates the amount of product formed and the amount of reactants used per unit time.

To define chemical equilibrium we need to ask some important questions about reactions: Does a reaction always run its full course so that all the reactants are used up

When all the reactants in a reaction are used up the reaction is said to have gone to completion

Does a reaction always proceed in the same direction or can it be reversed

In other words, does a reaction always proceed reactants products, or is it possible that a reaction will reverse and go products reactants

However, in some reactions the reactants form products (in a ), and the products can change back into reactants (in a )

Can a reaction reach a point where reactants are still present, but there does not seem to be any further change taking place in the reaction

In all reactions, as the amount of reactant in a reaction decreases the product is formed more slowly

In a reversible reaction, as the amount of product increases the reactant is formed more quickly

Eventually the rate of the forward reaction (reactants products) equals the rate of the reverse reaction (products reactants)

At this point there but there does not appear to be any further change taking place

Chemical equilibrium is the state of a reversible reaction where the rate of the forward reaction equals the rate of the reverse reaction

While a reaction is in equilibrium the concentration of the reactants and products are constant.Chemical equilibrium A reaction is in chemical equilibrium when the rate of the forward reaction equals the rate of the reverse reaction

In the bottle there is carbon dioxide () dissolved in the liquid

There is also gas in the space between the liquid and the cap

There is a constant movement of from the liquid to the gas phase, and from the gas phase into the liquid

However, if you look at the bottle there does not appear to be any change

The system is in equilibrium.Without chemical equilibrium life as we know it would not be possible

Another example of equilibrium in our everyday lives goes on within our very bodies

The haemoglobin has to be able to take up oxgen, but also to release it and this is done through changes in the chemical equilibrium of this reaction in different places in our bodies.haemoglobin(aq) + haemoglobin((aq)Haemoglobin, inside red blood cells in the lungs, bonds with oxygen

This oxyhaemoglobin moves with the red blood cells through the blood stream to cells throughout the body.This video is a good demonstration of how a reaction reaches equilibrium with time.Video: 27VFThe important thing for the students to understand in this experiment is that there is constant movement

Molecules at the surface of the water in the closed beaker are constantly evaporating, and gas molecules are constantly condensing

There is no change in the level of the liquid and the total number molecules in the liquid and the gas state remain constant.Point out that the level of water in the sealed container also drops initially, before finally remaining constant

This concept will help learners understand how the rate of the forward reaction decreases until equilibrium is reached.Evaporation is when a substance goes from the liquid phase to the gas phase (it evaporates)

Condensation is when a substance goes from the gas phase to the liquid phase (it condenses).The bottle contains water vapour (gas) and water droplets are condensing on the side of the bottle.An open system is one in which matter or energy can flow into or out of the system

In the liquid-gas demonstration we used, the first beaker was an example of an open system because the beaker could be heated or cooled (a change in energy), and water vapour (the matter) could evaporate from the beaker.Open system An open system is one whose borders allow the movement of energy and matter into and out of the system

A closed system is one in which energy can enter or leave, but matter cannot

The second beaker with the glass cover is an example of a closed system

The beaker can still be heated or cooled, but water vapour cannot leave the system because the glass cover is a barrier

Condensation changes the vapour to liquid and returns it to the beaker

In other words, there is no loss of matter from the system.Generally, some of the molecules at the surface of liquids and solids are moving into the gas phase

However, this is such a small fraction of the total volume of the liquid or solid that a reaction involving only solids or liquids can be considered a closed system.It is useful to simplify situations in science by dividing the world into the system we are studying, and the surrounding environment that might influence the reaction, but is not part of it.Closed system A closed system is one in which only energy can move into and out of the system

Matter cannot be gained by the system nor lost from the system

In a closed system it is possible for reactions to be reversible, such as in the demonstration above

In a closed system, it is also possible for a chemical reaction to reach equilibrium.Some reactions can take place in two directions