Electron Arrangement and Ionisation Energy

Question 1

State the 4 electron sub levels and their orbital numbers

Answer 1

S = 1 orbital
P = 3 orbitals
D = 5 orbitals
F = 7 orbitals

Question 2

What is an electron oribtal

Answer 2

A region within the atom where the electron is most likely to be found

Question 3

State and explain the electron configuration of Chrome

Answer 3

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵ - It takes less energy to put 1 electron in the 3d orbitals than to put 2 electrons in the 4s orbital

Question 4

State and explain the electron configuration of Copper

Answer 4

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰
OR
[Ar] 4s¹ 3d¹⁰

Question 5

State the electron configuration of Manganese

Answer 5

[Ar] 4s² 3d⁵ or 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

Question 6

Describe the periodic pattern of electron configuration

Answer 6

First period contains electrons only in 1st main level
Second period - 1st and 2nd main levels
Third period - 1st, 2nd and 3rd
Fourth period - 1st, 2nd, 3rd and 4th

Question 7

State Aufbau’s principle

Answer 7

lowest energy orbital filled first

Question 8

State Hand’s rule

Answer 8

Atomic orbitals of the same energy fill up singly before starting to pair

Question 9

Which orbital requires more energy to be filled and ionised? 3d or 4s

Answer 9

4s gets filled first USUALLY meaning it requires less energy, but also gets ionised first meaning it has more energy than the 3d orbital when filled.

Question 10

Define first ionisation energy

Answer 10

The energy needed to ionise a mole of an element by taking away a valance electron

Question 11

Explain the factors of first ionisation energy

Answer 11

Factors:
- Higher Nuclear Charge means higher ionisation energy due to higher EM attraction between the protons in the nucleus and the electrons
- Lower atomic radius means the outer electron shell is closer to nucleus so more energy is required to free the electron
- Less shielding means the electron has less negative repulsion and more attraction to the nucleus, this raises the ionisation energy required

Question 12

Describe and explain the trend in first ionisation energy going across period 2

Answer 12

General increase as you go across due to a decrease in radius because of higher nuclear charge. Al has one electron in the 2p orbital meaning it is more unstable than the Mg atom with a full 2s orbital. S requires less energy than P because it has one double pair in its 2p orbital making it more unstable than P with its complete 2p orbital of single electrons.

Question 13

First Ionisation Energy equation

Answer 13

X𝑔 → X𝑔ᐩ + e⁻

first ionisation always done in gaseous state

Question 14

How to determine the element from its successive ionisation energy

Answer 14

A dramatic increase in ionisation energy means a shell of electrons has been removed

Question 15

Write an equation for the third ionisation energy of Argon

Answer 15

Ar²ᐩ𝑔 → Ar³ᐩ𝑔 + e⁻

Question 16

What does successive ionisation energy prove

Answer 16

The existence of electron configuration shells as there is a clear jump between energy required