Exam Revision - Definitions Flashcards
The helium nucleus emitted when an unstable larger nucleus decays
Alpha particle
Equal to the number of protons in the nucleus (and is the same for every atom of the same element).
Atomic Number
A stream of particles and/or energy from a radioactive source.
Radiation
A particle found in the nucleus of an atom that does not have an electrical charge.
Neutron
A particle found inside an atom, such as a proton, neutron or an electron.
Subatomic Particles
A reaction that is self-sustaining as a result of the one step starting another.
Chain reaction
The time it takes for half of an isotope to decay.
Half-life
The splitting of a nucleus into two smaller pieces.
Nuclear fission
A process where atoms rearrange to form a new substance.
Chemical reaction
A written representation of a chemical reaction.
Chemical equation
A substance that comes out of (is made from) a chemical reaction.
Product
A substance that is put into a chemical reaction.
Reactant
A chemical equation that uses the chemical symbols to represent the chemical reaction.
Formula Equation
A universal law that states that mass cannot be created or destroyed.
Conservation of mass
A chemical reaction that happens without the input of energy.
Spontaneous
A chemical equation that does not have the same amount and type of atoms in the reactants and the products.
Unbalanced
A substance that changes colour under different acidic/basic conditions.
Indicator
A chemical reaction in which a fuel reacts with oxygen and produces heat as one of the products.
Combustion
A chemical compound that contains only carbon and hydrogen.
Hydrocarbon
A chemical reaction that takes in heat energy.
Endothermic
Reaction of a substance with oxygen.
Oxidation
The phenomenon whereby gases in the Earth’s atmosphere trap heat energy.
Greenhouse effect.
Storing carbon dioxide in geological formations.
Geosequestration
A circuit which has multiple loops.
Parallel circuit
The device used to measure the difference in potential energy between two points in a circuit.
Voltmeter
The unit of resistance.
Ohm
An energy source which converts stored chemical potential energy to electrical energy.
Battery
The point where the battery connects to the circuit.
Electrode
A battery which contains a liquid electrolyte.
Wet cell battery
A material which does not allow an electric current s through it.
Insulator
A wave where the particles in the medium vibrate at right angles to, the direction the wave is travelling in.
Transverse wave
A region which contains no particles.
Vacuum
The angle between the reflected ray and the normal.
Angle of reflection
An image which is larger than the object.
Enlarged image
A curved piece of transparent material which focuses light to produce an image.
Lens
Material which light can be transmitted through.
Transparent material.
Material in which some light is reflected and some passes through.
Translucent material
Material in which no light passes through as it is either absorbed or reflected.
Opaque material.
An image which forms when light rays actually cross.
Real image
The measure of how easily light travels through different media.
Refractive index
A flat mirror.
Plane mirror
The number of crests which pass a certain point in one second.
Frequency
An image which is smaller than the object.
Diminished image.
A lens which curves inwards.
Concave lens
A lens which curves outwards.
Convex mirror
The angle between the refracted ray and the normal.
Angle of refraction.
The angle between the incoming light ray and the normal.
The angle of incidence.
The point where parallel light rays converge after going throughout lens.
Focus
An image which is right-side up.
Upright image.
An image which is upside down.
Inverted image
An image which is mirrored.
Laterally inverted image
Light which contains all other colours of light.
White light
An imaginary line which stands at right angles to the surface of a lens or mirror.
Normal
An image which forms when light rays appear to cross but do not actually cross.
Virtual image
The distance from one crest to the next.
Wavelength
The top of a wave.
Crest
The bottom of the wave.
Trough
The middle part of a wave.
Equilibrium
The distance between the middle of a wave and the top or bottom of the wave.
Amplitude
The fundamental particles of matter, made up of protons, neutrons and electrons.
Atom
Atoms with the same number of protons but a different number of neutrons.
Isotopes
The mass of protons, neutrons and electrons that make up an atom.
Atomic weight.
A negatively charged particle in the atom, which moves in space around the nucleus.
Electron
A positively charged particle in the nucleus of an atom.
Proton
The spontaneous disintegration of certain atomic nuclei accompanied by the emission of alpha particles, beta particles or gamma radiation.
Radioactivity
An electron or positron (which has the same mass as an electron but the opposite charge) emitted when an unstable nucleus decays.
Beta particle
Why do atoms form ions?
To get full valence shells, which are more stable
What is an ion?
An atom with an electrical charge.
If there is two electron shells, which of these has the lowest energy.
The shell closest to the nucleus.
How do ionic bonds form?
By the transfer of electrons from one atom to another.
What is electrostatic attraction?
When opposite electrical charges are attracted to each other.
Positively charged ion.
Cation
Negatively charged ion.
Anion
The unit for voltage.
Volt
Opposition to the flow of the current.
Resistance
The difference in potential energy between two points in a circuit.
Voltage
The unit for current.
Ampere
A circuit where all components are on a single loop.
Series circuit
The positive electrode.
Cathode
The negative electrode.
Anode
The device used to measure the strength of a current.
Ammeter
A material which allows an electric current to pass through it.
Conductor
The flow of charge around a circuit.
Current
A solution which conducts electricity.
Electrolyte
A loop of wire which connects an energy source to an energy user.
Circuit
