Part 12 & 13 - Quantum Numbers & Fundamental Laws

principal quantum number (n)

• energy level

• determines the size of the particle

quantum number (ℓ)

• sub-shell / sub-level

• determines the shape

magnetic quantum number (m or ml)

• orbitals

• determines the orientation

spin quantum number (s or ms)

direction of the spin / electrons

paramagnetic elements

• elements that have unpaired electrons

• attracted to external magnetic field

diamagnetic elements

• elements that have completely paired electrons

• weakly repelled by magnetic field

ferromagnetic elements

• arises when the unpaired electrons of the atoms or ions in a solid are influenced by the orientation of the electrons in neighboring atoms or ions

• Fe, Co, Ni

Pauli’s exclusion principle

• ‘no two electrons can have the same set of 4 quantum numbers’

• ‘each atomic orbital can only accommodate 2 electrons’

Heisenberg’s uncertainty principle

‘it is impossible to determine simultaneously the electron momentum and position’

Aufbau building up principle

‘lower energy level are filled up’

Hund’s rule of maximum multiplicity

‘orbitals are filled up singly before pairing up’

principal quantum number

used to describe the approximate measure of the size of the electron cloud

spin quantum number

2 electrons occupying the same orbital differ in their _____

Law of Mass Action

according to this law, the rate of the reaction is proportional to the product of the concentrate of the reactants to the power of its coefficient in a balanced equation

Law of Conservation of Mass

states that during a chemical reaction, matter is neither created nor destroyed. The total mass of the reactants must equal to the total mass of the products.

Law of Definite Proportion (Proust’s Law)

states that a chemical compound always contains exactly the same proportion of elements by mass