Inorganic Chemstry

What are the 2 types of spectroscopy?

absorbtion and emission

How does absorbtion spectroscopy work?

electromagnetic radiation is directed at an atomised sample, radiation is then absorbed as electrons are promoted higher energy levels

How is an absorbtion spectrum produced?

by measuring how the intensity of absorbed light varies with wavelength

How does emission spectroscopy work?

high temperatures are used to excite the electrons within atoms; as the electrons drop to lower energy levels, photons are emitted

How is an emission spectrum of a sample produced?

by measuring the intensity of light emitted at different wavelengths

In atomic spectroscopy, the concentration of an element within a sample is related…

the intensity of light emitted or absorbed

When matter absorbs or emits electromagnetic radiation, it behaves like a stream of particles called…

photons

What does a photon carry?

quantisised energy proportional to the frequency of radiation

How do electrons behave?

as standing stationary waves in an atom, they vibrate in time but do not move in space

What are the 4 different orbitals?

s, p, d, f

Electrons within atoms have fixed amounts of energy called…

quanta

What is the principal quantum number?

n - indicates the main energy level for an electron and is related to the size of the orbital

What does the angular momentum quantum number determine?

l - the shape of the subshell and can have values between zero and n-1

What does the magnetic quantum number determine?

m - the orientation of the orbital and can have values between -l and +l

What does the spin magnetic number determine?

s - the direction of spin and can have values of +1/2 or -1/2

What is the aufbau principle?

electrons fill orbitals in order of increasing energy

What does Hund’s rule state?

when degenerate orbitals are avaliable, electrons fill each singly, keeping their spins parallel before spin pairing starts

What does the Pauli exclusion principle state?

no two electrons in one atom can have the same set of 4 quantum numbers, therefore, no orbital can hold more than 2 electrons and the 2 electrons must have opposite spins

2 electron pairs…

linear

3 electron pairs…

trigonal planar

4 electron pairs

tetrahedral

5 electron pairs…

trigonal bipyramidal

6 electron pairs

octahedral

What is a transition metal?

metals with an incomplete d subshell in at least one of their ions

What is oxidation

an increase in oxidation number

What is reduction?

a decrease in oxidation number

Compounds of the same transition metal in different oxidation states may have…

different colours

What does anion mean

negatively charged

Explain how a line is produced in an emission spectrum

Electrons promoted to higher energy levels, photons of light is emitted

Explain why there is a series of lines at discrete wavelengths in an emission spectrum

different electron transitions/ different energy levels

What does it mean when a molecule is bidentate?

it binds to two negative charges or lone pairs to a central atom/ion