Angle of refraction

Results

Angle of incidence       

20 

40

60

80

90

Angle of refraction

51.5

58

71

83

90

Edmodo revision sheet

Q1

define independent, dependant and controlled variable 

Independent -   Free from outside control

Dependant - something that relies on another 

Controlled variable - control variable has different meanings, depending on the area/place in which it is used. The control variable is something that is constant and unchanged in an experiment. 

Q2

When working with an acid you can prevent harmful risks by wearing the proper gear such as science glass. 

If you spill on your self and it hits your glasses instead of your eyes.

Q3

Models are used science because it is easier to understand things.

Chemistry

Q1 

What is the symbol for carbon, sodium, tungsten (you can use the periodic table)

Carbon=C, sodium=NA, tungsten=W

Q2

Define physical property and chemical property

Physical property's are colours, smell, appearances that do not change.

Chemical property's are pH levels, and reactivity.

Q3

Define an element, compound, molecule, mixtures, atomic number, atomic weight

Element- a group of protons, electrons, neutron

Compound- substances made up of 2 or more different element formed together.

Molecule- substances made up of 2 of the same elements.

Mixtures- 2 or more substances together that have no chemical change reaction.

Atomic number- atomic number tells you how many protons and electrons are in an atom

Atomic weight- protons plus the neutrons is the weight of the atom.

Q4

Name the element in group 3 period 3 

Scandium

Q5

Draw a picture of the boron atom

Absorption reflection and refraction

Absorption

The energy of the wave can be absorbed by the substance.

Where does the energy go

It causes some the particles in the substance to vibrate, so it has become heat energy.

Even substances which are transparent , like glass or water absorb some light. In perfectly clear water, light can only penetrate 50 m. By 100m down the ocean it is totally dark.

Reflection

This means to bounce off

Light always reflects at the same angle. At which it hits the reflecting surface

Important points

All waves can be reflected or they can bounce off things 

The reflection of sound wave causes echos 

The reflection of radio waves 

 

Refraction

This occurs when the light penetrates into a transparent substance, such as glass or water.

The light waves changes their speed and can change direction

Q1 when light waves strike any object, any 3 things can happen

List the 3 things

Reflection 

Refraction

Absorption 

Q2

Both the angle are the same

Q3

The smoother the surface the shinned it is 

Q4

A

It happens In water

B

It changes the shape of the image

C

Because the clear water changes the light waves distorting the image.

The law of reflection states that the angle of incidence ( the light hits the surface ) .Angle of incidence is the angle between the light ray and the normal. The angle of reflection is the angle between the reflected and the normal.

Light

It can be made artificially 

Is a source of renewable energy 

The sun is a natural source of light

Light produces heat

Can be intensified by lens.

How it enables us to see

What produces light

Can light bend 

Define

 luminous- bright or shinning in the dark

Transparent- allowing light to pass through so that objects behind can be seen

Opaque- don't see through

Translucent- allowing light through but be able to see detailed images

Reflection- light bouncing off reflecting light.

Light enables us to see. The major producer of light are stars. The we can see is referred to as visible light. It is also referred to as white light. White light is a mixture of all different oculus of light. Light is a form of energy that falls within the electromagnetic spectrum. Light travels in straight lines in waves. The waves cannot bend, each colour of light has silghtly different wavelength. The different colours of light that makes up white light can be seen in a rainbow.

Light can be 

Absorbed by objects

Bent by objects- refracted

Bounces off - reflected 

The thinnest possible beam of light is called a light ray.

Bush fires

C

Define drought

A prolonged period of abnormally low precipitation; a shortage of water resulting from this.

What causes drought

Drought is caused when warm moist air is pushed to South American , which produces rain there and drought here.

What impact does drought have 

Death of animals 

Little or no water

Introduction species

An introduced species, is any living organism that has been relocated into a new ecosystem by human activity. Humans have been responsible for the introduction of many plants and animals into Australia. Some of these introduced species have caused significant changes to the native ecosystems.

Bioaccumiltion

Bioaccumulation

Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism.  Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost. 

Year 9 Class work 

Using the internet, on the designated sites, find definitions and answer the following questions. Your answers must be in your own words and you need to reference your sources.

Q1

Define ‘bioaccumulation’. 

Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism.

Q2

Identify 3 examples of chemicals that might accumulate in living organisms.

Pesticides, led and mercury 

Q3

Go to the following site: http://www.ec.gc.ca/MERCURY/EH/EN/eh-ec.cfm
Outline the steps in bioaccumulation of mercury.  

Give 3 effects of mercury poisoning.

Death, birth defects and brain damage

Q4

Go to the following site: http://www.mercury.utah.gov/bioaccumulation.htm. This is a government site so the information should be reliable. Read to the bottom of the page. Are the steps for bioaccumulation the same as you already outlined above or can you add more information.

Q5

On the bar at the bottom of the page click on ‘mercury facts’. What is mercury? Where is it found? What are some uses of mercury and how does it get into the food chain?

Q6

Write a short paragraph about the Minamata Disaster, Japan. 

Using the following sites: 
http://www.3dchem.com/molecules.asp?ID=90,  http://www.abc.net.au/news/stories/2008/05/11/2241160.htm, 
http://en.wikipedia.org/wiki/DDT

Do some research on the chemical DDT. 
Find out: What is DDT? How does it get into the food chain? What are its effects on animals as it builds up in them? How can we prevent DDT getting into the environment? What steps have countries taken to reduce DDT in the environment?

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