Inorganic Flashcards
Name the electromagnetic radiations in increasing frequency
Radiowaves, microwaves, infrared, visible light, ultraviolet, x-ray, gamma
What are photons?
When electromagnetic radiation is absorbed or emitted by matter it behaves like a stream of particles. A photon carries quantised energy proportional to the frequency of radiation.
How are electrons promoted to lower energy levels?
An atom emits a photon of light energy when an excited electron moves from a higher energy level to a lower energy level.
what is evidence for the existence
of these energy levels?
The light energy emitted by an atom produces a spectrum that is made up of a series of lines at discrete (quantised) energy levels.
What is absorption spectroscopy?
In absorption spectroscopy, electromagnetic radiation is directed at an atomised sample. Radiation is absorbed as electrons are promoted to higher energy levels.
What is emission spectroscopy?
In emission spectroscopy, high temperatures are used to excite the electrons within atoms. As the electrons drop to lower energy levels, photons are emitted.
What are orbitals?
electrons behave as waves which vibrate in place. There are different sizes and shapes which are called orbitals. One orbital can hold two electrons
the principal quantum number, n
the main energy level for an electron and is
related to the size of the orbital
The angular momentum number, l
determines the shape of the subshell and
can have values from zero to n −1
The magnetic quantum number, ml
determines the orientation of the orbital and can have values between −l and +l
The spin magnetic number, ms
determines the direction of spin and can have vales of -1/2 or +1/2
The aufbau principle
electrons fill orbitals in order of increasing energy
Hund’s rule
when degenerate orbitals are available, electrons fill each singly, keeping their spins parallel before spin pairing starts
The pauli exclusion principle
no two electrons in one atom can have the same set of four quantum numbers, therefore, no orbital can hold more than two electrons and these two electrons must have opposite spins
orbitals in isolated atoms are..?
degenerate
Why are electrons paired?
Electron pairs are negatively charged and repel each other. They are arranged to minimise repulsion and maximise separation.
What are d-block transition metals?
The d-block transition metals are metals with an incomplete d subshell in at least one of their ions.
Which transition metals are an exception with the aufbau principle?
chromium and copper
Why do chromium and copper atoms not follow the aufbau principle?
These exceptions are due to the special stability associated with the d subshell being half-filled or completely filled.
What happens to the electrons when the first row on transition metals are ionised?
When atoms from the first row of the transition elements form ions, it is the 4s electrons that are lost first rather than the 3d electrons.
How can the same transition metal be different colours?
Compounds of the same transition metal in different oxidation states may have different colours.
What is oxidation?
Oxidation can be defined as an increase in oxidation number.
What is reduction?
Reduction can be considered as a decrease in oxidation number.
What is a ligand?
Ligands may be negative ions or molecules with non-bonding pairs of electrons that they donate to the central metal atom or ion, forming dative covalent bonds.
