Definitions Flashcards
Acceleration
The change in speed divided by the time taken for the change
Acid
A substance which turns blue litmus paper red and has a pH of less than 7. Acids have a sour taste and a sharp feel.
Acid rain
Rainwater which has a pH less than 5.5
Activity series
A list of metals placed in order of their reactivity
Adaption
A structure or habit that helps an organism survive in its habitat.
Aerobic respiration
Oxygen is needed to release energy from food
Alkali
A substance which reacts with an acid to form a salt and water.
Alkali metals
Group 1 on the periodic table eg. Sodium
Alkaline earth metals
Group 2 of the periodic table. Eg. Calcium
Alloy
A mixture of metals
Alternating current
A current that constantly changes direction
Altimeter
An instrument that measures change in pressure and translated into height above sea level.
Amp
The unit of current
Anaerobic respiration
Oxygen is not used to release energy from food
Area
The amount of surface that covers an object
Asexual reproduction
New individuals are formed from only one parent
Atom
The smallest part of an that still has the properties of that element
Atomic number
The number of protons in an atom of that element
Base
A substance that neutralises an acid to form salt and water. Bases turn red litmus paper blue.
Beating tray
A device used to collect animals
Biotechnology
The use of living to produce useful products
Bond
Force of attraction that holds atoms together
Canines
Teeth that are long and pointed and used to grip and tear food.
Carnivore
An animal that eats other animals only
Catalyst
Substances that alter the rate of a chemical reaction but are not used up themselves
Cellulose
The substance which make cell walls and provides fiber in the human diet
Cell wall
Found outside the plants membrane
Centre of gravity of a body
A point about which the turning effects due to gravity are balanced
Chemical change
A reaction in which a new substance is formed
Chemical energy
Energy stored inside materials in the chemical bonds holding them together
Chlorination
The addition of chlorine to water to kill bacteria
Chloroplasts
Contain the green pigment called chlorophyll
Competition
Takes place hen two or more organisms require something that is in short supply
Compunds
Made up of 2 or more different types of atom chemical combined
Concentrated solution
A solution that contains a large amount of solute in a small amount of solvent
Conductor (electrical)
An object that allows a charge to move
Conductor (heat)
An object that allows heat to travel through it
Conservation
The protection and wise management of natural resources
Contraception
The prevention of fertilization or pregnancy
Corrosion
An undesirable process whereby a metal changes to its oxide or some other compound by combining oxygen with air
Covalent bond
A bond that consists of a pair of electrons shared between two non metals.
Crystallization
The formation of crystals by cooling a saturated solution or by evaporation solvent off
Decibel
A unit of sound
Decomposers
Organisms that feed on dead plants and animals
Density
The mass of each cubic meter of an object
Diffusion
The name used to describe the way particles in gases and liquids spread throughout the space in which they are placed
Digestion
The breakdown of food
Dilute solution
A solution containing a small amount of solute and a large amount of solvent
Convection
The transfer of heat through liquids and gases by the mass movement of particles
Direct current
The flow of charge in one direction only around a circuit
Dispersal
The carrying of the seed (and the surrounding fruit) as far away as possible from the parent plant
Dispersion
The breaking up of white light into its 7 colours
Distillation
A process used to separate two miscible liquids with different boiling points eg. Alcohol and water
Diode
A device that allows current to flow in one direction only
Echo
The reflection of sound
Ecology
The study of the relationship between plants animals and their environment
Electrical energy
Energy caused by moving charges
Electric current
The movement of charge through a material
Electrolysis
A chemical reaction produced by using electricity
Electromotive force
Force from a battery to cause current
Electron
A negatively charged particle in an atom
Electronic configuration
The arranged of electrons in an atom
Elements
Substances made up of only one type of atom
Energy
The ability to do work measured in joules (j)
Enzyme
A chemical (protein) that speeds up chemical reactions without having being used up
Equilibrium
A still object i.e. Not spinning or moving. Either stable, unstable or neutral
Evaporation
The changing of a liquid to a gas
Excretion
The removal of the waste products from the body of chemical reactions in the body
