Words Suitable for Pupils Taking the Science 13+ Common Entrance Exam

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Science Dictionary January 2001Page 1.

Words

used in

Science

Words suitable for pupils taking the Science 13+ Common Entrance exam

Name______

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Science Dictionary April 2014 Page 1.

ABDOMENThe last part of an insect’s body (after the head and the thorax). It is the part that contains the digestive and reproductive organs. In a human it is the soft part under your lungs (where your intestines and are).

ABSORBENTAbsorbent means ‘soaks up water’. A towel will be absorbent.

ABSORPTIONWhen light hits an object and does not get reflected back (eg when light hits a piece of black paper it is absorbed, this is why the paper looks black)

ACIDA liquid with a pH value less than pH 7

Acids:i. usually sour to taste (do NOT taste anything in the lab.)

ii. will neutralise an alkali.

iii.turn BLUE litmus indicator RED

examples of some acids: lemon juice (citric acid), vinegar (acetic acid), hydrochloric acid (found in your stomach) and sulphuric acid (found in car batteries).

Acids are often corrosive which means they will attack and eat into substances such as acid and skin.

ACID RAINRain water which has dissolved gases from the air and become acid is called ACID RAIN. Gases which cause acid rain include sulphur dioxide (formed when fossil fuels like coal and oil are burnt) and nitrogen dioxide (comes from car exhausts).

NOTE: all rain water is slightly acid due to carbon dioxide which is naturally present in the air.

ADAPTIONIn order to help them survive, animals and plants have developed special features to help them fit into their habitat. These special features are called adaptions (examples: Fish have a streamlined body to help them move through the water, camels have large feet to stop them sinking into the sand, Frogs have webbed feet to help them swim.

AIRAir is the mixture of gases that surround the Earth. Air consists of nitrogen (about 78%), oxygen (about 21%), argon (about 1%) and a variety of other gases (including carbon dioxide, helium and water vapour).
Uses for air: Supports Gliders, planes and parachutes. Needed for things to burn. Kites. Blows sailing boats along.
Air does have weight. There is no air on the Moon

AIR PRESSUREIt is the moving particles continuously colliding against the edge of a container that causes the pressure in a gas. How to increase the pressure:

i)By squashing the particles closer together (eg pumping up a tyre or blowing up a balloon)

ii)By warming the gas. This makes the particles vibrate faster (this is why a balloon expands when heated)

(See ATMOSPHERIC PRESSRE)

AIR RESISTANCE Air resistance happens when air tries to slow down a moving object (like a parachute or car). Another name for air resistance is drag. It is a kind of friction.
A streamlined object has only a little air resistance.

ALGAESingle celled plants. Reproduce asexually by binary fission. Live in wet places. Have no leaves or roots.

ALIMENTARY CANAL (gut)

The tube that links the mouth to the anus down which food travels.

ALKALIA liquid with a pH value greater than 7

Alkalis:i.feel soapy to touch

ii. will neutralise an alkali

iii.turn RED litmus indicator BLUE

examples: washing soda (sodium carbonate), caustic soda (sodium hydroxide), ammonia soln., garden lime (calcium hydroxide), indigestion mixture (eg magnesium hydroxide).

Alkalis are caustic and can burn your skin.

Alkali in your eyes is particularly dangerous.

ALUMINIUMAluminium is very light metal. It is used to make kitchen foil, saucepans and sometimes good quality bicycle frames). Aluminium is a good conductor of heat and electricity.

AMMETERAn instrument used for measuring current. It is placed in series with the conductor being tested and has a very LOW resistance.

AMNIONA water filled sac (containing AMNIOTIC FLUID) that helps support and protect the developing embryo.

AMPHIBIANSOne of the VERTEBRATES. An animal that lays soft jelly covered eggs in water. Have smooth moist skin. Adults live on land or in water. Young live in water and go through metamorphosis. e.g. frog.

AMPLITUDEThe size of a wave. The amplitude of a sound wave determines what its VOLUME will be.

ANNELIDSSegmented worms with bristles on each segment e.g. earthworm or leach.

ANTAGONISTIC MUSCLES Antagonistic muscles are muscles that work in pairs. An example of antagonistic muscles are the biceps and triceps. The biceps lift the arm up and triceps pull it down. When the biceps contract the triceps relax and visa versa,

ANTHERMale part of a flower. Where pollen is made.

ARACHNIDSAnimals that have 4 pairs of legs, 2 parts to the body eg spider, scorpion.

ARTERIESCarry blood away from the heart.

ARTHROPODSAnimals that have many pairs of jointed legs and an exoskeleton. The arthropods are divided into several smaller groups eg insects, arachnids and crustaceans.

Examples: woodlouse, spider, fly.

ASEXUAL REPRODUCTION

A form of reproduction where NO fertilization required. Examples of asexual reproduction:

i) Production of spores in non-flowering plants eg moss, and fungi.

ii)Budding eg in cactus III) runners eg in the strawberry)

iv) Tubers eg in potato).

v) Binary fission in single cells eg in amoeba (a single-celled animal) or in algae (single-celled plants).

The way all individual cells multiply. Disadvantage: daughter cells identical to parent cells. Advantage: A quick process. Rapid colonisation.

ATOMThe smallest possible part of any substance. Some substances only have one kind of atom and these are called elements.

Compounds consist of at least two different kinds of atom.
The smallest atom is a hydrogen atom.

BACTERIABacteria are microscopic organisms that can be found anywhere. Some bacteria are helpful like those found in the soil that make things rot or the bacteria used to turn milk into yogurt. Some are harmful and can make us ill, causing stomach upset or a sore throat. (See micro-organism).

BALANCED DIETOur diet is what we eat. A balanced diet is eating all the nutrients but in the right amounts.
A balanced diet needs to include carbohydrate (for energy), Protein (for growth), vitamins and minerals (to keep us healthy) along with fibre and water. (see Diet)

BIRDOne of the VERTEBRATES. A warm blooded animal that lays hard-shelled eggs on land. Bodies covered in feathers eg thrush.

BLADDEROrgan in a human that stores urine. Urine leaves the bladder through a tube called the URETHRA. In males the urethra leaves the body through the penis.

BACTERIABacteria are microscopic organisms that can be found anywhere. Some bacteria are helpful like those found in the soil that make things rot or the bacteria used to turn milk into yogurt. Some are harmful and can make us ill, causing stomach upset or a sore throat. (See micro-organism).

BALANCED DIETOur diet is what we eat. A balanced diet is eating all the nutrients but in the right amounts. This would include lots of fruit and vegetables, pasta and cereals (for vitamins, carbohydrates and fibre). Some fish, meat or cheese (for protein) and only a small amount of fat, salt or sugar.
A balanced diet needs to include carbohydrate (for energy), Protein (for growth), vitamins and minerals (to keep us healthy) along with fibre and water. (see Diet)

BLADDEROrgan in a human that stores urine. (Urine is the yellow liquid you get rid of when you go to the toilet) The kidney removes poisonous waste from the blood, changes it into urine and stores it in the bladder

BLOODA fluid in our body that consists of a clear watery liquid known as plasma and a variety of other larger particles eg

red blood cells: these carry oxygen around the body and give the blood its red colour.

white blood cells: these help fight disease

platelets:very small cells that help the blood clot

Uses for blood:i) Transports food and oxygen to the cells.

ii) Transports waste away from the cells.

iii)Helps protect the body from infection.

iv) Helps regulate the body temperature (37C)

BLOOD VESSELA tube that carries blood around the body. Large blood vessels are called arteries or veins. Small ones are called capillaries. Arteries carry blood away from the heart and veins carry blood back towards the heart.

BOILA liquid boils when it gets hot enough so that it evaporates inside (forming bubbles) as well as at the surface.

BOILING POINTThe boiling point of a liquid is the temperature at which it starts to boil

The boiling point of water is 100°C

BRAINControls and coordinates all the major functions of the body. Where all the nerves meet

BUNSEN BURNERA piece of apparatus that burns gas and is used to heat apparatus. It has an air hole that controls the flame temperature by regulating the flow of air into the burner.When the air-hole is open: A hot, blue, roaring flame.When the air-hole is closed: A cooler, smoky, luminous yellow flame. Not used to heat apparatus as it is very sooty.

BURNWhen something burns it reacts with oxygen giving off heat and light.
Burning is an example of a permanent change.

CARBON DIOXIDEIs acolourless gas used by plants during photosynthesis and breathed out by humans as a waste product. It is the gas that forms the bubbles in fizzy drinks and is also sometimes put in fire extinguishers.
To test for carbon dioxide bubble it through lime-water which will turn cloudy.
Carbon dioxide is a compound of carbon and oxygen and has the formula CO2

CAPILLARIESTiny blood vessels that carry blood to the individual cells.

CAPILLARY ATTRACTIONA force which drags liquids up fine holes or cracks. It is what causes porous objects soaking up water and allows blotting paper and towels to absorb

CARACTERISTICAnything about of animal or plant inherits from its parents is a characteristic

eg. Characteristics of a shark: streamlined body, sharp teeth

Characteristics of a duck: webbed feet, waterproof feathers

CARBOHYDRATECarbohydrates are starch or sugar like sweets, bread, pasta.

Carbohydrates provide us with energy.
Carbohydrates contain the elements carbon, hydrogen and oxygen.

CARBONCarbon is one of the chemical elements. All living things contain carbon.

Carbon is black. Coal and charcoal are made mostly of carbon. When you ‘burn’ a piece of toast you are left behind with carbon. Diamond and graphite are both made of pure carbon. When carbon burns it forms carbon dioxide gas.

CARBON DIOXIDEIs a colourless gas used by plants during photosynthesis and breathed out by humans as a waste product. It is the gas that forms the bubbles in fizzy drinks and is also sometimes put in fire extinguishers. Carbon dioxide turns lime-water cloudy.
Carbon dioxide is a compound of carbon and oxygen and has the formula CO2

CARNIVOREAn animal that eats only meat. (Carnivorous)eg thrush, pike, ladybird

CELLThe basic unit of all life. All cells contain a nucleus, cytoplasm , MITOCHONDRIAand a cell membrane. Plant cells also have a cell wall, a large vacuole and sometimes chloroplasts.

CELLA cell is another name for a battery. A battery would normally be several cells joined together. The cell provides the chemical energy to push the electric current around a circuit

CELL MEMBRANE

The living outer boundary of the cell. The membrane is selective in allowing what passes through it (into or out of the cell).

Cells build up into tissues, tissues into organs and organs into organisms. Found in ALL cells.

CELL WALLThe dead, outer edge to the cell. gives the cell strength. Made of cellulose. Found ONLY in plant cells.

CHANGE STATE:The three states of matter are solid, liquid and gas.
A substance can be made to change state by heating it up or cooling it down

Changing from a solid to a liquid (by heating it) = melt

Changing from a liquid to a gas or vapour (by heating it) = evaporate

Changing from a gas to a liquid (by cooling it down) = condense

Changing from a liquid to a solid (by cooling it down) = solidify
All examples of changing state are reversible changes.

CHEMICAL CHANGE

When a new substance is formed and a chemical reaction has taken place.

Examples of a chemical reaction are: decomposition, combination, combustion, rusting, photosynthesis, oxidation and neutralisation

Signs that a chemical change is taking place are:

i. Heat given out ii. Colour change

A chemical change will usually be permanent.

eg Burning magnesium (to form magnesium oxide)

CHEMICAL REACTION

Any process where a new substance is formed (see Chemical Change)

CHLOROPLASTSThe part of a PLANT CELL that is green. Found only in certain plant cells above ground. Chloroplasts contain chlorophyll which makes them look green. They are where photosynthesis is carried out.

CHLOROPHYLLChlorophyll is the substance that makes plants look green.
It is needed for photosynthesis to take place.

CHORDATESAnimals with a backbone. Have an internal skeleton. eg Lion, snake, frog.

COELENTERATES

Jelly-fish/sea anemones. Have central mouth surrounded by stinging tentacles eg Portuguese Man of War

COLD-BLOODEDAnimals whose body temperature alters with the temperature of the surroundings eg fish. All animals except for birds and mammals are cold blooded.

COMBUSTIONAnother name for BURNING. A combustible material is one that burns easily.

Products of combustion: the chemicals produced when something is burnt. eg. The products of combustion when wax is burnt are carbon dioxide and water.

COMMUNITYA collection of all the animals and plants that live in a particular area.

COMPOUNDThe substance formed when two or more elements are chemically combined together.

eg HYDROGEN (element) + OXYGEN (element) = WATER (compound).

Other compounds: Copper sulphate, magnesium oxide, calcium carbonate

Note: the elements in a compound cannot be separated without a chemical reaction taking place.

CONDENSECondensing is what happens when a gas turns to a liquid due to being cooled down.
For example if steam touches a cold mirror it will condense and turn to drops of water. (See Change of State). Condensing is a reversible change.

CONSUMER Consumers are the animals in a food chain (Plants are called producers)

The first animal in a food chain is called a primary consumer

The second animal is called a secondary consumer.

Example food chain

Grass rabbit Fox
(producer) (Primary consumer) (secondary consumer)

COPPERCopper is pink metal. It is a very good conductor of heat and electricity.
It is the metal that wires are made from. It is a metallic element.

CRUSTACEANSAnimals that usually have 5 pairs of legs, eg crab, woodlouse. Belong to the phylum of Arthropods.

CRYSTALLISATION

The process for obtaining the solute from a solution by warming the solution until crystals start to appear and then letting the solution cool.

eg obtaining copper sulphate from copper sulphate solution.

CRYSTALSA crystal is a solid in which the particles are arranged in a REGULAR pattern. Crystals will often have flat sides and straight edges.

CURRENTThe rate at which electricity moves along a conductor. Measured in amperes (amps) using an instrument called an ammeter.

CYTOPLASMThe living contents of a cell (excluding the nucleus). Found in ALL cells.

DAYThe time it takes a planet to revolve once on it axis. One Earth day = 24 hours

DECOMPOSEWhen a compound is split apart into two (or more) simpler substances, usually by heating.

eg if blue (hydrated) copper sulphate is heated it will decompose into anhydrous copper sulphate (a white powder) and water.

DECOMPOSEAnother name for ‘rot’. A dead animal or plant will slowly decompose (rot away) if left in the ground.. It is the bacteria and fungi in the soil that make an animal decompose.

DECOMPOSERAn animal that lives on the rotting remains of other organisms. Decomposers help in the recycling of dead material returning essential nutrients to the ground. eg fungi, bacteria, various beetles, worms.

DENSITYMass per unit volume.

This means the mass (in grams) of one cubic centimetre of a substance.
The unit of density is grams per cubic centimetre (g/cm3).

Density is calculated as Density = mass / volume

eg a block of iron with a volume of 3cm3 has a mass of 27g . This tells us the density of iron = 27÷ 3, = 9g/cm3.

This means that the mass of one cubic centimetre of iron is 9 grams.
The density of water is 1 g/cm3. Anything with a density more than that of water will sink and anything with a density less than water will float.
A substance with a LOW density will take up more space (volume) than a substance with a high density.

DIAPHRAGMA sheet of muscle across the body, above the abdomen but below the lungs, that enables us to breath.

DIGESTIONDigestion is what happens to your food after you eat it. The food is broken down by enzymesinto simple chemicals that are then absorbed into the body. Digestion takes place mostly in the intestine. (Although digestion actually starts in the mouth)

DIODEAn electrical component that only allows a current to flow in one direction.

DISEASEA disease is an illness caused by a fungus, bacterium or virus.
Examples : Sore throat or upset tummy are often caused by bacteria.
Flu and measles are caused by a virus.
A lot of plant diseases are caused by fungi.
We can help stop the spread of disease by doing the following...

by washing our hands after going to the toilet or before preparing food.
by storing food at the right temperature (below 5°C) and cooking it properly.
by not sharing cups.

by using a handkerchief (or hand) over your mouth when you cough or sneeze.

DISTILLATIONThe name of the process used for obtaining the SOLVENT from a SOLUTION

eg obtaining pure water from sea water.