Topic 2- Foundations in Chemistry Flashcards
atomic number
number of protons in the atom
isotope
elements with the same number of protons but different number of neutrons
relative isotopic mass
mass of an isotope of an element compared to 1/12 th the mass of an atom of carbon-12
relative atomic mass
the weighted mean mass of an atom of an element compared to 1/12 yh the mass of an atom of carbon-12
cation
positive ion
anion
negative ion
amount of substance
number of particles in a substance
molecular formula
number of atoms of each element in a molecule
empirical formula
simplest whole-number ratio of atoms of each element in a compound
relative molecular mass
the weighted mean mass of a molecule of a compound compared with 1/12th the mass of an atom of carbon-12
relative formula mass
the weighted mean mass of the formula unit of a compound compared with 1/12th the mass of an atom of carbon-12
hydrated
a crystalline compound containing water molecules
water of crystallation
water molecules that are bonded into a crystalline structure of a compound
anhydrous
containing no water molecules
standard solution
a solution of a known concentration
molar gas volume
the volume per mole of gas molecules at a stated temperature and pressure
limiting reagent
the reactant which is not in excess, which will be used up first and stop the reaction
atom economy
measure of efficiency of a chemical reaction
strong acid
an acid that dissociates completely in a solution
weak acid
an acid that dissociates only partially in a solution
alkali
a type of base that dissolves in water forming hydroxide ions
neutralisation
a chemical reaction in which an acid and a base react together to form a salt
redox reaction
a reaction involving reduction and oxidation
orbital
region around the nucleus that can hold up to two electrons with opposite spins
s-block
highest energy electron in the s subshell
p-block
highest energy electron in the p subshell
d-block
highest energy electron in the d subshell
ionic bonding
electrostatic attraction between oppositely charged ions
covalent bonding
electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atom
dative covalent bond
a shared pair of electrons in which the bonded pair has been provided by one of the bonding atoms only
tetrahedral
4 bond pairs and 0 lone pairs with a bond angle of 109.5
pyramidal
3 bond pairs and 1 lone pair with a bond angle of 107
non-linear
2 bond pairs and 2 lone pairs with a bond angle of 104.5
linear
2 bond pairs and 0 lone pairs with a bond angle of 180
trigonal planar
3 bond pairs and 0 lone pairs with a bond angle of 120
octahedral
6 bond pairs and 0 lone pairs with a bond angle of 90
electronegativity
a measure of the attraction of a bonded atom for the pair of electrons in a covalent bond
non-polar bond
no charge separation across a bond or in a molecule
polar bond
bonded electron pair shared unequally between the bonded atoms
intermolecular forces
an attractive force between molecules
London forces
temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles
permanent dipole
a small charge difference that does not change across a bond, with partial charges on the bonded atoms
hydrogen bond
a strong dipole-dipole attraction between an electron-deficient hydrogen atom of -NH,-OH or HF on one molecule and a lone pair of electrons on a highly electronegative atom
oxidation state
the oxidation number
