2.4 Electronic Configuration

Question 1

What is the most stable electronic configuration of an atom

Answer 1

Is the one that has the lowest amount of energy therefore the subshell with lowest energy are filled first

Question 2

What is the real electronic configuration of chromium and what is it’s expected electronic configuration

Answer 2

Chromium has the electronic configuration of [Ar] 3d54s1 rather than the expected [Ar] 3d44s2

Question 3

What is the real electronic configuration of copper and what is it’s expected electronic configuration

Answer 3

Chromium has the electronic configuration of [Ar] 3d104s1 rather than the expected [Ar] 3d104s2

Question 4

Why do chromium and copper does not have the expected electron arrangements

Answer 4

This is because the 3d54s1 qnd 3d104s1 electron arrangements are more energetically stable

Question 5

Why is group one and 2 called the s-block

Answer 5

Because the outer electrons of their elements are in the s sub shell

Question 6

Why is Group 13 to 18 called the p-block

Answer 6

Because the outer electrons of their elements are in the p sub shell

Question 7

Why are the transition elements called the d-block (except the two series)

Answer 7

Because the outer electrons of their elements are in the d sub shell

Question 8

What is spin pair repulsion

Answer 8

Electrons in the same region of space (orbitals) repel each other because they have the same charge. They minimize this repulsion by spinning in opposite directions.

Question 9

Why are the spins of the electrons in the same orbital in opposite directions

Answer 9

To minimise repulsion

Question 10

What do the electrons do to minimize this repulsion

Answer 10

Whenever possible, electrons will occupy separate orbitals in the same sub shell. so these electrons have their spin in the same direction

Question 11

What is a free radical

Answer 11

It is a species with one or more unpaired electros

Question 12

What are some examples of free electrons

Answer 12

Chlorine. Groups of atom can also be free radicals eg H3C

Question 13

How is an unpaired electron in a free radical represented

Question 14

In general, the electrons in outer shells are removed first when metal ions are forming positive ions. What is the exception to this rule?

Answer 14

The d-block elements behave slightly differently. But when atoms of a d-block elements lose electrons, the 4s electrons are lost first.