Science RevisionEND OF YEAR EXAM

PERIODIC TABLE

PERIODIC TABLE

WHO INVENTED ITDmitri Mendeleev he is a Russian scientist who had made the periodic table many have tried but Dmitri has done it eventually

NUTRITION AND DIGESTION

EATING A BALANCED DIETWHAT MAKES A BALANCED DIET:

DIFICIENCY DISEASES/NUTRITION LACKING/SYMPTOM/WHAT FOOD CAN TREAT DISEASE

LIGHT

PROPERTIES OF LIGHT LIGHT ALWAYS TRAVELS IN DEAD STRAIGHT LINES

1)THE LIGHT TRAVELS IN STRAIGHT LINES FROM THE SHEEP TO THE TRACING PAPER SCREEN THROUGH THE PINHOLE. BECAUSE THE HOLE IS SMALL,ONLY ONE RAY GETS FROM EACH POINT.

2) THE IMAGE OF THE SHEEP SEEN BY THE FARMER IS UPSIDE DOWN AND CROSSED OVER. THIS IS BECAUSE THE RAYS OF LIGHT CROSS OVER INSIDE THE CAMERA AS SHOWN:

REFLECTION AND REFRACTIONLIGHT REFLECT OFF MANY THINGS. THE LAW OF REFLECTION:

ANGLE I=ANGLE R

DO DRAW THIS RAY DIAGRAM MAKE SURE YOU DRAW STRAIGHT LINES AND GET THE ANGLES THE SAME- USE A PROTRACTOR

REFLECTION AND REFTRACTIONWHEN LIGHT GOES THROUGH LESS DENSE MEDIUM TO A MORE DENSE MEDIUM: LIGHT BENDS TOWARDS THE NORMAL EXP.AIR TO GLASS

WHEN LIGHT GOES THROUGH MORE DENSE TO LESS DENSE : LIGHT BENDS AWAY FROM THE NORMAL EXP.GLASS TO AIR

COLOUR DISPERSAL OF WHITE LIGHT: SPECTRUM

IN THE SPECTRUM YOU CAN SEE THE COLOURS OF A RAINBOW THE VIOLET IS BENT THE MOST

CLICK ON THE LINK BELOW FOR EXPLANATIONhttps://youtu.be/KgqV975EtA0

COLOURED FILTERSFILTERS ONLY LET ONE LIGHT THROUGH. ALL THE OTHER FILTERS ARE ABSORBED BY THE FILTER- THEY DON'T GET THROUGH

Plants and photosynthesis

Photosynthesis equation

carbon dioxide + water (+ light

energy) → glucose + oxygen

photosynthesis test for starch (leaf in light)what you need:

leaf plant been in sun

beaker

bunsen burner

ethyl alcohol

tweezers

Method1.heat a plant leaf in boiling water for 30 seconds (this stops its

chemical reactions)

2.heat it in boiling ethanol for a few minutes (this removes most of its colour)

3.wash with water and spread onto a white tile

4.add iodine solution from a dropping pipette

The starch should turn blue or black meaning starch is present in the leaf there for collecting photosynthesis.

Chloroplast(plant cell)

This diagram is a plant cell number 7 is called chloroplast it contains a green chemical chlorophyll which traps light for photosynthesis. The chloroplast gives the green colour to the leaf.

Diagram of a sliced leafa What are the names of the parts labelled A–G? Use these words to help you: air space, chloroplast, cuticle, guard cell, palisade cell, spongy cell, stoma.b Water vapour is lost from leaves. Arrow P shows water vapour leaving the cells. What is the name of this process?c Arrow Q shows the water vapour escaping from the leaf. What is the name of this process?2 a In which cells does most photosynthesis happen?b How are these cells adapted to carry out photosynthesis?c Where are these cells located in a leaf?d Why do you think they are in this position?3 Suggest a reason for each of these observations:a Leaves have a large surface area.b Leaves are thin.c Leaves often grow in such a way that they do not shade one another.d Stomata are shut at night.4 a Name three types of substance that a plant makes using glucose.b What is each type of substance used for?

Glucose

The eye

diagram of eye

THE EYE Lens- transparent, biconvex, flexible disc behind the Iris attached by the suspensory ligaments to the ciliary muscles The function of the lens it Focuses light on the retina Retina- The lining of the back eye contain two types of photoreceptor cells-Rods- sensitive to dim light and black and white cones- sensitive to colour a small area foven the middle of the retina has many more cells than photoreceptor cells The function of the retina it contains the light receptors The cornea- front part of the tough outer coat the sclera is convex and transparent The function of the cornea is refract light bend it as it enters the eye Optic nerve-Bundle of sensory neurones at the back of the eye The function of the optic nerve is carries impulsive from the eyes to the Brain The iris-Pigmented -The colour of your eyes- Silverlight cannot pass through. it's muscles contract and relax to the alter the size of a pupil. The function of the Iris is it control how much light enters the pupil ciliary Muscles- muscles connected to the lens by suspensory ligamentsThe function of the ciliary muscles is it is adjust shapes of the lens to make it more or less curved so as it increases or decreases reflection of light suspensory ligaments- connected to ciliary muscles through the lens and hold the lens in place the function of the suspensory ligaments that it's slacken or stretched the ciliary muscles contract or relax to adjust the thickness and the Curvature of the lens

SOUND

bell jar experiment

FREQUENCY AND PITCH

Fuels and Energy

What do we mean by energy:Here are 4 types of energy:

Chemical energy

Electrical energy

Heat & light energy

Nuclear energy

Non renewable and renewable energy sourcesExamples of energies:

Renewable Non renewable

Wave energy oil

Tidal energy coal

Hydroelectric energy wood

What's the difference?Non-renewable: Renewable:

Cannot be replaced Can be replaced

Will run out Will run out

Eg. coal Eg. solar energy

Carbon cycle (fuels and energy cont.)

Carbon Cycle

Global warming/climate change/Greenhouse effectGlobal warming:the amount of co2 in the atmosphere increasing

Climate Change:It's the change of the atmosphere and the climate/weather

Greenhouse effect: It's when the atmosphere of the earth goes colder and it would be below freezing level, furthermore the molecules would act like the gas.

What is Climate?Long term average of a region's weather.

Average rainfall

Average hrs of sunshine

Average tempreature

Magnets

Magnetic Materials

The 3 magnetic metals are:

Iron

Nickel

cobalt

Magnetic Non magnetic

Galvanised steel Soft aluminium

Zinc plate Cooper

Magnetic stainless steel Zinc

steel Bronze

Bar magnet lines of force

A bar magnet has got two poles;North and South. The magnetic field of a magnet is strongest at the poles because this is where the magnetic field lines are close together.