IB Chemistry Topic 3 Definitions
This page contains our IB Chemistry definitions for topic 3. By learning each one of these definitions, you will fully cover the content for IB Chemistry 'Classification of Matter'.
anion
Non-metals that gain valence electrons to gain a negative charge
atomic radius
Distance from nucleus to valence electron
cation
Positive ions. Commonly metals that lose valence electrons to gain a positive charge.
chiral carbon
A carbon bonded to four different groups
cis-isomerism
Attached groups are the same on the same side of the bond plane
cis-trans isomerism
Isomerism that only occurs with bond rotation restriction and communicates symmetry around the bond plane based on group identity
complementary colours
two colours opposite one another on a colour wheel
complex ion
Complex composed of a central d-block metal ion coordinate bonded to electron-rich ligands
configurational isomers
Molecules with different arrangements that require bond breaking and reforming to align
conformational isomers
Molecules with different spatial arrangements that can be aligned by bond rotation
coordination number
Number of lone pairs bonded to the metal ion
diastereomer
Optical isomers that are not mirror images of each other
E-isomerism
The groups with the highest atomic numbers are on opposite sides of the bond plane
E/Z isomerism
Isomerism that only occurs with bond rotation restriction and communicates symmetry around the bond plane based on atomic number
electron affinity
Energy change during electron addition to an isolated mole of gaseous atoms
electron repulsion
electrons try to move as far away from each other due to the repelling negative charges
electronegativity
Relative measure of the attraction an atom has for a shared pair of electrons when covalently bonded to another atom
electrostatic attraction
The attraction of opposite charges between the positive nucleus and negative electrons
enantiomers
Optical isomers that are mirror images of each other
fingerprint region
A unique pattern of absorption in the wavenumber region of 1400-400 cm-1
first ionization energy
The energy required to remove one electron from amole of atoms in a gaseous atoms, expressed in kJ/mol
group
one column of the periodic table
H NMR
A method that provides information about the environment of hydrogen atoms
hydrogen environment
The atom that the hydrogen is attached to and atoms bonded to that atom
index of hydrogen deficiency (IHD)
A measure of saturation of an organic molecule
infrared spectroscopy
A method that shines infrared light on molecules and measure absorption
ionic radius
Distance from nucleus to valence electron of cation or anion
ligand
Neutral molecule or anion with a non-bonding pair of electrons (commonly water)
mass spectrometry
A method that vaporizes and ionizes a sample molecule, and then deflects its into different fragments with magnetic field
monodentate ligand
One non-bonding electron pair
nuclear charge
The amount of positive charage in the nucleus, proportional to the number of protons
optical isomerism
Isomerism where two molecules have the same molecular and structural formuals but are not super-imposable
organic compound
A compound containing carbon
oxidation state
Akin to ionic charge, it represent the number of electrons gained or lost in order to form a covalent bond with another atom
period
one row of the periodic table
Periodic table
The periodic table is table of all known elements organized in order of increasing atomic number
periodicity
The repeating pattern of physical and chemical properties shown by different periods
polarimeter
A device that detects the optical activity of enantiomers
polydentate ligand
More than one non-bonding electron pair
primary carbon
A carbon bonded to one other carbon
primary nitrogen (amine)
A nitrogen bonded to one carbon
quaternary carbon
A carbon bonded to four other carbons
racemic mixture
A mixture with equal amounts of enantiomers, which is optically inactive
secondary carbon
A carbon bonded to two other carbons
secondary nitrogen (amine)
A nitrogen bonded to two carbons
shielding effect
The effect of inner electrons taking nuclear charge away from the valence electrons
skeletal formula
Simplified stuctural formulas that only show lines and assume a carbon at each junction is fully saturated with hydrogens
Spin-spin coupling
Produces the splitting pattern on H-NMR due to the influence of Hydrogen nuclei on other neighbouring Hydrogen nuclei
stereoisomers
Molecules with the same structural formula but different spatial arrangements
structural isomer
A molecule with the same molecular formula but a different structural formula than another molecule
tertiary carbon
A carbon bonded to three other carbons
tertiary nitrogen (amine)
A nitrogen bonded to three carbons
trans-isomerism
Attached groups are the same on opposite sides of the bond plane
transition metal
Elements that form ions with an incomplete d-orbital in one of more of its oxidation states
valence shell
Outermost energy level of an atom
visible light
the part of the electromagnetic spectrum the human eye can see. contains wavelengths from 400nm to 700nm
X-ray crystallography
A method that shines X-rays on bonds and uses a sensor to detect the diffraction of the X-rays to measure bond length
Z-isomerism
The groups with the highest atomic numbers are on the same side of the bond plane
Next Up
You have completed the topic 3 definitions for IB Chemistry - continue with related resources below or explore the full IB Chemistry course from the IBO.
Other topic 3 resources