Question | Answer |
Acceleration | The Change in Speed divided by the time taken for the change |
Acid | A substance that turns blue Litmus red and has a pH of less than 7. Acids have sour tastes and a sharp feel |
Acid Rain | Rainwater with a pH of less than 5.5 |
Activity Series | A list of metals placed in order of how reactive they are |
Adaptation | A structure or habit that helps an organism to survive in its habitat |
Aerobic Respiration | In this type of respiration Oxygen is used to release energy from food |
Alkali | A substance which reacts with an acid to form a salt and water. Alkalis are bases dissolved in water |
Alkali Metals | The elements of Group I of the periodic table, e.g. Sodium |
Alkaline Earth Metals | The elements of Group II of the periodic table, e.g. Calcium |
Alloy | A mixture of metals |
Alternating Current (A.C.) | An electrical current that constantly changes direction |
Altimeter | An instrument that measures changes in pressure and translates it into height above sea level |
Amp | The Unit of Current |
Anaerobic Respiration | In this type of 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 one parent only |
Atom | The smallest part of an element that still has the properties of that element |
Atomic Number | The number of protons in an atom of that element |
Absolute Zero | The lowest theoretical temperature (0K = -273°C) where all molecular activity ceases |
Acceleration | Rate of change of velocity |
Acid | A compound that yields hydrogen ions (H+) when in aqueous solution Acids have a sour taste and turn blue litmus red |
Alkali | A base that is soluble in water |
Alloy | A substance formed by the combination of two or more elements, at least one of which must be a metal |
Anion | A negative ion |
Atomic number | The number of protons in an atom |
Atomic symbol | The letters representing each of the elements |
Atomic Mass | The average mass of an atom |
Atoms | Composite particles of protons, neutrons and electrons The smallest part of a substance that can take part in a chemical reaction |
Base | A compound that yields hydroxide (OH- ) ions when in aqueous solution Bases have a bitter taste, feel soapy and turn red litmus blue |
Boiling point | The temperature at which a liquid turns to a vapour |
Bond | A chemical link between atoms |
Capacitance | The ability to store an electric charge |
Carbohydrates | The major energy source within plants and animals: sugars, starches and glucose polymers |
Carbon | The basic element in all organic compounds |
Catalyst | A substance that speeds up a chemical reaction but is not used up in it |
Cation | A positive ion eg Ca++ |
Cell | The smallest independent part of an organism |
Charge | Either positive or negative |
Chemical Formula | The ratio of elements in a substance example: the chemical formula of common salt is NaCl, sodium and chlorine in a ratio of 1:1 |
Chemical Reaction | The transformation of substances by the rearrangement of their atoms |
Chromosomes | DNA molecules that contain the set of instructions required to build and maintain cells |
Compound | A substance containing more than one element |
Conduction | Heat or electricity transfer from molecular or atom to atom, eg: heat passing along a metal bar |
Convection | Heat transfer through the movement of a fluid, eg: warm air rising |
Covalent bond | A bond formed between atoms that share pairs of electrons |
Crystal | Solid substance with a regular geometirc arrangement of atoms |
Density | The mass per unit volume in a substance |
Diffraction | The bending of light when it passes from one transparent medium to another example from water to glass or air |
Diffusion | The random movement of molecules within a fluid |
DNA | Deoxyribonucleic Acid - Genetic material located inside the nucleus |
Elasticity | The ability of a body to regain its original shape after deformation |
Electric Current | A flow of electrons through a conductor, the size of the current is proportional to the rate of electron flow |
Electrons | Negatively charged atomic particles |
Electromagnetic waves | Waves with both an electric and magnetic component They are: radio, micro, infra-red, visible light, ultraviolet, X and gamma rays |
Electrolyte | An ionic solution that is an electrical conductor |
Element | A substance composed of atoms all with the same atomic number or A substance that cannot be split chemically into smaller substances |
Endothermic reaction | A reaction in which heat is absorbed ie: melting or boiling |
Energy | The ability to do work Work is done by transferring energy from one form to another For example the chemical energy in a fuel is converted to thermal energy as it burns |
Enzymes | Biological catalysts, proteins that control specific processes within the body |
Equilibrium | A stable situation in which products and reactants are balanced |
Evaporation | The change of state of a substance from a liquid to a gas below its boiling point |
Evolution | Natural selection, the survival of the fittest, is the driving force behind it Fitness is the ability to survive and reproduce, not necessarily a measure of physical fitness |
Exothermic reaction | A reaction from which heat is lost eg: combustion |
Fats | Molecules of fatty acids or glycerol |
Fission | Splitting the nucleus of an atom into smaller units |
Fluid | A liquid or gas |
Force | A push or a pull An action (transfer of energy) that will accelerate a body in the direction of the applied force |
Frequency | The rate as which periodic motion repeats itself |
Friction | A measure of the resistance felt when sliding one body over another |
Fusion | 1 - Change of state of a substance from a solid to a liquid 2 - The joining together of two atomic nuclei |
Gametes | Sex cells (Spermatozoa or Ova) that carry the genes donated by each parent |
Gene | A unit of inheritance - A section of DNA |
Gravity | The attraction that all bodies have for one another |
Halogen | Highly reactive gases forming group 7 of the periodic table example Chlorine |
Heat | A form of energy or The internal energy of a body (substance) |
Hydrocarbon | Compounds containing only hydrogen and carbon atoms |
Inertia | Tendency of a body to remain at rest or move in straight line |
Inheritance | Determined by a set of chromosomes These originate in the parents and are passed on to an offspring during fertilisation It follows then that since chromosomes are inherited, all the features of an organism must be inherited |
Ion | Atom with an unbalanced electrical charge caused by the loss or gain of one or more electrons |
Ionic bond | An bond formed by the electro-magnetic attraction between ions of opposite charge |
Isotope | An element that has more or less neutrons than normal Many isotopes are radioactive |
Kinetic energy | The energy possessed by a body in motion |
Latent heat | The amount of energy required to change a solid to a liquid or liquid to a gas |
1st Law of Thermodynamics | The amount of energy in the universe is fixed It cannot be created or destroyed only changed from one state to another |
2nd Law of Thermodynamics | Heat cannot pass from a cold to a hot body The opposite condition where heat always flows from a hot to a cold body is valid for the whole universe |
Lens | Light modifier Convex lenses focus and concave lens diffuse light waves |
Light | The visible part of the electromagnetic spectrum: red, orange, yellow, green, blue, indigo and violet - White light is a combination of all the above colours- A form of Energy |
Magnet | A body which produces a magnetic field All magnets are di-poles and follow the rule that like poles repel and unlike poles attract |
Mass | The quantity of matter in a body |
Metals | Elements characterised by their opacity, malleability and thermal and electrical conductivity |
Molecular formula | The number and types of atom in a molecule For example the molecular formula of methane is CH4, one atom of carbon and four atoms of hydrogen |
Molecule | A group of atoms bonded together It is the smallest part of a substance that retains the chemical properties of the whole |
Moment | A rotating effect See torque |
Momentum | The product of mass x velocity Momentum is conserved in any system of particles |
Monomers | Small molecules that link together to form a polymer |
Neutralisation | A reaction in which the characteristics of an acid or base disappear |
Neutrons | Particles with zero charge forming part of an atomic nuclei |
Newtons Laws of Motion | Classical laws which enable the prediction of the path of any object from a grain of sand to entire galaxies: |
Newtons 1st Law of Motion | A body will remain at rest or move with a constant velocity unless acted upon by an outside force |
Newtons 2nd Law of Motion | The acceleration of a body is proportional to the applied force This is expressed by the universal formula: Force = mass × acceleration |
Newtons 3rd Law of Motion | For every action there is an equal and opposite reaction |
Noble gases | Elements with zero valency They form group 0 or 8 in the periodic table and are non-reactive |
Nucleus | Organelle containing the chromosomes or that part of an atom containing the protons and neutrons |
Organelles | Specialized organs within cells |
Organic Compounds | Substances that contain Carbon |
Ozone | An isotope of oxygen that blocks ultra-violet radiation Normally found in the stratosphere |
pH Scale | The strength of acids and bases Pure water has a pH value of 7, acids have a lower value and bases higher |
Phase Changes | Freezing, Melting, Boiling, Condensing, Subliming, Evaporation |
Photosynthesis | The conversion of water and carbon-dioxide by plants into glucose and oxygen Light is used as an energy source |
Polymerisation | The repetitive bonding of small molecules (monomers) to produce large molecules (polymers) |
Polymers | Long chain molecules such as PVC, nylon or DNA produced by the polymerisation of monomers |
Potential Difference | The voltage difference between two points Electricity flows from a high to low level of potential |
Potential Energy | Amount of useable energy within a body at rest |
Power | Amount of work done per second |
Products | The substances produced in a chemical reaction |
Proteins | Amino acid polymers with specific biological functions, especially the growth, regeneration and repair of cells |
Protons | Positively charged particles forming part of atomic nuclei - 3 quarkhadrons |
Radiation | Transfer of heat between bodies without a change in the temperature of the intervening medium or Any release of energy from its source |
Radioactivity | The spontaneous release of energy from atomic nuclei |
Reactants | The substances that take part in a chemical reaction |
Refraction | The bending of a light wave as it passes from one medium to another, eg from air to water |
Relative Atomic Mass (Mr) | The mass of an atom relative to one atom of carbon Carbon has a Mr of 12 |
Reproduction | Reproduction is the process by which a new organism is produced |
Resistance | Opposition to current flow in a conductor |
Resonance | A state where the natural frequency of a body equals an applied frequency |
Respiration | The production of energy by the oxidisation of glucose |
Specific Heat | The heat capacity of a body |
Strain | The deformation of a body under an applied load |
Stress | The measure of the force acting on a body |
Temperature | How hot one body is when compared to another |
Torque | The tendency of a body to rotate under an applied force |
Valency | A measure of the reactivity of an element |
Velocity | The rate of change of distance with respect to time |
Viability | The ability to survive to adulthood |
Viscosity | The internal friction of a fluid, thick fluids have a high viscosity and thin fluids low |
Weight | The gravitational force exerted on a mass |
Work | The amount of energy transferred to a system |
Zygote | A fertilised egg, the fusion of a male and female gamete |
Seven Characteristics of Life | Nutrition, Respiration, Excretion, Growth, Reproduction, Movement and Response |
Excretion | The removal of waste matter from the body |
Respiration | The release of energy from food in a cell |
Reproduction | The formation of new organisms |
Nutrition | The way an organism gets its food |
Response | Reacting to changes in the surroundings |
Vertabrate | An animal with a backbone |
Invertabrate | An animal without a backbone. |
Plant cells consists of .. | Cell wall, Cell Membrane. Nucleus, Chloroplasts, Cytoplasm (and Large Vacuoles) |
Animal Cells consist of three main parts | Cell membrane, Nucleus, Cytoplasm (and Small Vacuoles). |
What do you use to identify Plants and Animals? | A Key |
Cytoplasm | A watery fluid found between the nucleus and cell membrane. |
Tissues | Tissues are a group of similar cells which carry oyut the same function, e.g. red blood cells carry oxygen |
An Organ | An Organ is a structure that contains two or more tissues working together,e.g. the heart. |
A System | A number of Organs working together, e.g. The digestive system |
Eyepiece | The Lens on a microscope closest to the eye. |
Focus knobs | Allow the image in a microscope to be seen clearly. Two types - Coarse and Fine. Use Coarse first then fine. |
Stage | Holds the microscope slide using clips. |
Mirror or Light | Used to illuminate (light up) the slide. |
Coverslip | A thin square piece of glass used when making up a slide. |
Iodine Solution | Used to test for starch and stain onion cells |
Total magnification in a microscope is calculated by .. | Multiplying the power of the eyepiece lens by the power of the objective lens being used. e.g. 10 x 40 = 400 times. |
Objective lens | Lenses located on the nosepiece of a microscope. Each gives a different magnification, e.g. x 4, x 10, x 40. |
Epidermis | The outer layer of cells covering an organism. |
Six Constituents of a Balanced Diet | Carbohydrates, Fats, Proteins, Vitamins, Minerals and Water |
Anaemia | Lack of Iron leading to a poor red blood cell count. |
Food Pyramid | Guideline Diagram of the types and amounts of food that should be eaten to maintain a balanced diet. |
Five Food Groups | Cereals, Bread and Potatoes. Fruit and Vegetables. Dairy Products. Meat and Fish. Other types of food. |
The Amount of Food a Person Needs Varies due to .. | Age. Gender. Activity Levels. Health. |
Test for Starch | Iodine turns blue/black (positive test) with starch. It remains a red/brown colour if no starch is present (negative test). |
Test for a reducing sugar | Benedict's solution (Blue in colour) plus dissolved food sample in a heated water bath. A brick/red colour indicates a positive test |