chemistry - chapter 2 & 3

atomic mass

atomic mass

mass of a single atom of a chemical element, including the mass of the subatomic particles (proton, neutron and electron)

relative atomic mass

ratio of the average mass of atoms of an element in a given sample to one unified atomic mass unit

mass spectrometry

process by which atomic mass of atoms/molecules is determined

continuum spectra

the entire range of colours present

emission spectra

only specific colours present

absorption spectra

specific colours missing

1st IE

the energy required to remove one mole of electrons from one mole of gaseous atoms

atomic radii

size of the atom determined by the distance from the centre of the nucleus to the boundary of the surrounding cloud of electrons

ionic radii

size of an atom when it loses/gains electrons

electronegativity

measure of the ability of an atom in a molecule to attract electrons to itself

electron affinity

energy released when an electron is added to an atom

oxidation state

a representation of an imaginary electronic state of an atom in a molecule

transition metal

an element whose atom has an incomplete d sub-shell, and can give rise to cations with an incomplete d sub-shell

ligands

an atom, molecule or ion that has lone pairs of electrons that can be donated to the central metal ion, thus forming dative covalent bonds

dative covalent bonds

a covalent bond where both electrons in a bond pair come from the same atom

coordination number

number of dative covalent bonds from the ligands to the central metal ion

denticity

number of atoms in a single ligand that bind to a central atom in a coordination complex

diamagnetism

a property of all materials and produces a very weak opposition to an applied magnetic field

paramagnetism

a property of substances with unpaired electrons and produces magnetisation proportional to the applied field in the same direction

ferromagnetism

largest effect producing magnetisation sometimes in order of magnitude greater than the applied field (Fe, Ni, Co)

process of mass spectrometry

1. vaporisation

2. ionisation

   1. atoms hit with high-energy electrons to knock out electrons from them to produce positively-charged ions

3. acceleration

   1. accelerated through an electric field

4. deflection

   1. positive ions separated and deflected by magnetic field

   2. higher charge, lighter ions → deflect more

5. detection

   1. detection of ions → signals sent to recorder

   2. strength of signal is a measure of the number of ions with that particular mass-to-charge ratio

physical properties of d-block elements (6)

1. high mp

2. high tensile strength

3. malleable

4. ductile

5. good conductor of heat

6. good conductor of electricity

chemical properties of d-block elements (5)

1. variable oxidation state

2. can form coordinate complex

3. have magnetic properties

4. catalytic

5. can form coloured compounds

complex

consists of a central metal ion surrounded by ligands forming dative covalent bonds with the ion

factors affecting colours (4)

1. metal ion identity

2. ligand identity

3. oxidation state of metal ion

4. shape of complex ion