A Level Chemistry Edexcel Definitions
questions and answer
isotope - Atoms of the same element that have different mass numbers
relative atomic masses - weighted mean mass of an atom on an element
compared to 1/12 mass of an atom of carbon-12
relative isotopic mass - The mass of an individual atom of a particular isotope
relative to 1/12 of the mass of an atom of carbon-12
quantum shell - the energy level of an electron
orbital - A region within an atom that can hold up to two electrons with opposite
spins.
Hund's rule - electrons will occupy the orbitals singly before pairing takes place
Pauli Exclusion Principle - two electrons cannot occupy the same orbital unless
they have opposite spins
, A Level Chemistry Edexcel Definitions
questions and answer
first ionisation energy - The energy required to remove an electron from each
atom in one mole of atoms in the gaseous state
periodicity - A regularly repeating pattern of atomic, physical and chemical
properties with increasing atomic number
electronegatiity - the ability of an atom to attract a bonding pair of electrons in a
covalent bond
dipole - created by equal but opposite charges that are separated by a short
distance
hydrogen bond - an intermolecular interaction between a hydrogen atom bonded
to a molecule more electronegative than hydrogen and another atom
disproportionation - the simultaneous oxidation and reduction of an element in a
single reaction.
basic oxide - oxides of metals that react with water to form metal hydroxides and
with acids to form salt and water
questions and answer
isotope - Atoms of the same element that have different mass numbers
relative atomic masses - weighted mean mass of an atom on an element
compared to 1/12 mass of an atom of carbon-12
relative isotopic mass - The mass of an individual atom of a particular isotope
relative to 1/12 of the mass of an atom of carbon-12
quantum shell - the energy level of an electron
orbital - A region within an atom that can hold up to two electrons with opposite
spins.
Hund's rule - electrons will occupy the orbitals singly before pairing takes place
Pauli Exclusion Principle - two electrons cannot occupy the same orbital unless
they have opposite spins
, A Level Chemistry Edexcel Definitions
questions and answer
first ionisation energy - The energy required to remove an electron from each
atom in one mole of atoms in the gaseous state
periodicity - A regularly repeating pattern of atomic, physical and chemical
properties with increasing atomic number
electronegatiity - the ability of an atom to attract a bonding pair of electrons in a
covalent bond
dipole - created by equal but opposite charges that are separated by a short
distance
hydrogen bond - an intermolecular interaction between a hydrogen atom bonded
to a molecule more electronegative than hydrogen and another atom
disproportionation - the simultaneous oxidation and reduction of an element in a
single reaction.
basic oxide - oxides of metals that react with water to form metal hydroxides and
with acids to form salt and water
