Wednesday, 30 October 2013

Angle of refraction

Results
Angle of incidence       
20 
40
60
80
90

Angle of refraction
51.5
58
71
83
90


Wednesday, 16 October 2013

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












Wednesday, 9 October 2013

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.

Tuesday, 8 October 2013

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.