Terminology Flashcards
Homogenous mixture
A mixture of uniform composition and in which all components are in the same state/phase
Heterogenous mixture
A mixture of non-uniform composition and of which the components can be easily identified.
Electrical conductor
A material that allows the flow of charge
Thermal conductor
A material that allows heat to pass through easily
Electrical insulator
A material that prevents the flow of charge
Thermal insulator
A material that does not allow heat to pass through it.
Diffusion
The movement of atoms/molecules from an area of high concentration area of low concentration
Boiling point
The temperature of a liquid at which its vapour pressure equals the external atmospheric pressure
Melting point
The temperature at which a solid, given sufficient heat, becomes a liquid.
Isotope
Atoms of the same element having the same number of protons, but different numbers of neutrons
Valence electrons
The elections found in the outermost orbital of an atom
Pauli’s Exclusion Principle
Maximum of two electrons per orbital provided that they spin in opposite directions.
Atomic orbitals
The most probable regions in space where electrons that have specific energy corresponding to the orbital are found
Hund’s rule
No pairing in p-orbitals before there is at least one electron in each of them
Heisenberg’s Uncertainty Principle
It is impossible to determine both the velocity and the position of an electron at the same time
Atomic radius
The mean distance from the nucleus to the border of the outer orbital
First Ionisation Energy
The energy needed per mole to remove the first electron from an atom in the gaseous phase
Electron-affinity
The energy released when an electron is attached to an atom/molecule to form a negative ion
Electronegativity
A measure of the tendency of an atom in a molecule to attract bonding electrons.
Brownian motion
The random motion of microscopic particles in suspension in a liquid or gas.
It is caused by collisions between these particles and the molecules of the liquid or gas.
Temperature
Average kinetic energy of particles
Law of conservation of mass
The total mass of the particles before a state change and the total mass of the particles a state change remains after constant
