Electron Orbitals

Question 1

2s orbital

Answer 1

1 node, higher energy, 2 electrons max.

Question 2

3s orbital

Answer 2

2 nodes, 2 electrons max.

Question 3

What is the electron configuration of Potassium (19)

Answer 3

1s(2)2s(2)2p(6)3s(2)3p(6)4s(1)

Question 4

What is the order for filling electron orbitals?

Answer 4

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p

Question 5

2p orbital

Answer 5

The lowest energy p orbital. 1 linear node = 2 alternate phase lobes. May be occupied by six electrons max, 2 in each of; 2px, 2py and 2pz.

Question 6

3p orbital

Answer 6

1 linear and 1 circular node = 2 opposite lobes, each in 2 different phases. 6 electrons max

Question 7

4p orbital

Answer 7

1 linear and 2 circular nodes. 6 electrons max

Question 8

3d orbital

Answer 8

Lowest energy d orbital. 2 planar nodes = 5 d orbital shapes. 10 electrons max

Question 9

The Principal Quantum Number (n)

Answer 9

Indicates the energy levels of an orbital (3s… n=3). Also indicates the number of nodes through n-1

Question 10

Angular Momentum Quantum Number (l)

Answer 10

Describes the shape of the orbital and therefore angular distribution. May take any value between 0 and n-1. Eg. When n=3, l = 0 1 and 2

Question 11

Magnetic Quantum Number (ml)

Answer 11

Describes the orientation of orbitals. Includes all values between -l and +l. E.g. n=3 so l=2 and ml = -2, -1, 0, 1, 2

Question 12

Spin Quantum Number

Answer 12

Describes the spin of the electron. Ms = either +1/2 or -1/2

Question 13

Pauli Exclusion Principal

Answer 13

No 2 electrons may be in the same quantum state

Question 14

The Aufbau Principle

Answer 14

Electrons in atoms generally exist in their lowest possible energy state (ground state)

Question 15

Hund’s Rule

Answer 15

Every orbital in a subshell will be occupied by one electron before any orbital in a subshell can be occupied by 2 electrons. All electrons in subshells organised singly will have the same spin.

Question 16

Effective Nuclear Charge (Z eff)

Answer 16

The positive charge felt by an electron in a multi electron atom. The closer an electron is to the nucleus the closer Z eff will be to Z.
Outer electrons are partially shielded so Z eff is much lower than Z.

Question 17

Nuclear Charge (Z)

Answer 17

Equal to the number of protons in a nucleus

Question 18

(Trend) Across a period, Z eff ___?

Answer 18

Increases, as electrons are attracted more strongly to the nucleus.

Question 19

(Trend) Down a group, Z eff ___?

Answer 19

Decreases as electron orbitals are further away from nucleus = greater shielding

Question 20

(Trend) Anionic radii have a ____ Z eff than their neutral atoms

Answer 20

Smaller, as electrons have been gained = larger radii

Question 21

(Trend) Cationic radii have a ____ Z eff than their neutral atoms

Answer 21

Larger, as electrons have been lost = smaller radii

Question 22

Ionisation Energy (E i)

Answer 22

First I.E is the amount of energy required to completely remove an electron from an atom. Second I.E for the second etc.

Question 23

(Trend) Ionisation energy _____ across a period

Answer 23

Increases, as electrons are attracted more strongly to the nucleus

Question 24

(Trend) Ionisation energy _____ down a group

Answer 24

Decreases, as electrons are attracted less strongly to the nucleus

Question 25

Electron Affinity (E ea)

Answer 25

The energy change when an electron is added to an atom in the gas phase. Energy is released = electron affinity (negative E i).

Question 26

(Trends) Metals have a ____ E i

Answer 26

Low, as they readily lose electrons

Question 27

(Trend) Non-metals have a ___ E i

Answer 27

High, as they readily gain electrons

Question 28

Electronegativity

Answer 28

The ability of an atom to attract bonding electrons. Fluorine is the electronegative element

Question 29

(Trend) Electronegativity _____ across a period

Answer 29

Increases

Question 30

(Trend) Electronegativity _____ down a group

Answer 30

Decreases

Question 31

1s Orbital

Answer 31

No nodes, low energy, 2 electrons max.

Question 32

What is the p orbital bond order for diatomic molecules?

Answer 32

1s, 2sσ, 2sσ, 2pσ, 2pπ, 2pπ, 2pσ*