Unit 1 Topic 2 ✓

Question 1

What is Quanta?

Answer 1

Quanta is a fixed amount of energy

Question 2

What is Heisenberg’s uncertainty principle?

Answer 2

Heisenberg’s uncertainty principle states that it’s impossible to determine simultaneously with high precision, both the momentum and position of an electron

Question 3

What is an Atomic orbital?

Answer 3

An atomic orbital is an area in space where the probability of finding an electron is more than 95%

Question 4

What is Pauli Exclusion Principle?

Answer 4

Pauli exclusion principle states that no two electrons in any atom can have the same set of four quantum numbers, and an orbital can’t contain more than two electrons (with opposite spin)

Question 5

What is the Principal quantum number ‘n’

Answer 5

The principal quantum number is the energy level (shell) where the electron is found

e.g. n=1, n=2…

Question 6

What is the Angular momentum number? ‘l’

Answer 6

The angular momentum number is the shape of the orbital within the energy level

e.g. l = 0 is an ‘s’ orbital

Question 7

What is the Magnetic quantum number? ‘mI’

Answer 7

The magnetic quantum number is the orientation of the oribital in space (its 3D position)
It is dependant on the shape of the orbital (‘l’)

Question 8

What is the Spin magnetic quantum number? ‘ms’

Answer 8

The spin magnetic quantum number determines the direction an electron spins (clockwise, or anti-clockwise)

NOTE: An orbital can hold max two electrons, with opposite spins

Question 9

What is the Aufbau principle?

Answer 9

The Aufbau principle states that electrons fill orbitals in order of increasing energy

Question 10

In terms of angular momentum number ‘l’:

What is an ’s’ orbital?

Answer 10

An ‘s’ orbital is spherical in shape and can hold max 2 electrons, with opposite spin.
Each energy level has one ‘s’ orbital.

NOTE: Max 2 electrons per sub-shell

Question 11

In terms of angular momentum number ‘l’:

What is a ‘p’ orbital?

Answer 11

A ‘p’ orbital is a dumb-bell shape that can hold max 2 electrons, with opposite spin.
Energy level n=1 has no ‘p’ orbitals, n=2 and above have 3.
‘p’ orbitals in an energy level are degenerate - they have equal energy

NOTE: Max 6 electrons in sub-shell

Question 12

In terms of angular momentum number ‘l’:

What is a ‘d’ orbital?

Answer 12

A ‘d’ orbital is a double dumb-bell shape that can hold max 2 electrons, with opposite spin.
Energy level n=1-2 have no ‘d’ orbitals, n=3 and above do (up to 5)
‘d’ orbitals in an energy level are degenerate - they have equal energy

NOTE: Max 10 electrons

Question 13

In terms of angular momentum number ‘l’:

What is an ‘f’ orbital?

Answer 13

An ‘f’ orbital is a complex shape. Energy level n=1-3 have none, n=4 and above do.

NOTE: You dont need to know the 7 posibble shapes

Question 14

What is Hund’s rule?

Answer 14

Hund’s rule states where there are degenerate orbitals in a subshell, electrons fill each one singly with the same spin before pairing will occur

Question 15

What is Ionisation Energy? (IE)

Answer 15

Ionisation energy is the energy required to remove one mole of electrons from one mole of gaseuous atoms/ions

NOTE: 1st IE/ 2nd IE