Electron configurations

Question 1

what are the rules of when electrons fill the orbitals of atoms

Answer 1

• an electron will occupy the lowest energy subshell
• max number of electrons in any 1 orbital is 2 ( they must have opposite spin)
• where a number of orbitals of equal energy are available one electron goes in each before any pairing occur and electrons singly occupied orbitals must have the same spin ( same direction of arrow)

Question 2

Why does only one electron go in each orbital of equal energy before pairing

Answer 2

electrons repel each other so its lower energy if they occupy different regions of space in the atom

Question 3

Lithium configuration (3 electrons)

Answer 3

1s²2s¹

Question 4

Nitrogen configuration (7 electrons)

Answer 4

1s²2s²2p³

Question 5

How many atomic orbitals are in the subshell s

Answer 5

1

Question 6

How many atomic orbitals are in the subshell p

Answer 6

3

Question 7

How many atomic orbitals are in the subshell d

Answer 7

5

Question 8

How many atomic orbitals are in the subshell f

Answer 8

7

Question 9

Shell 1 - No. subshells, names of subshells, total no. electrons held

Answer 9

1, 1s, 2

Question 10

Shell 2 - No. subshells, names of subshells, total no. electrons held

Answer 10

2, 2s, 2p, 8

Question 11

Shell 3 - No. subshells, names of subshells, total no. electrons held

Answer 11

3, 3s, 3p, 3d, 18

Question 12

Shell 4 - No. subshells, names of subshells, total no. electrons held

Answer 12

4, 4s, 4p, 4d, 4f, 32

Question 13

What is different about subshell 4s and 3d

Answer 13

4s is slightly below the 3d subshell in energy, so the 4s subshell fills up before the 4s. This means the 4th shell starts before the 3rd is full

Question 14

How to find the group of an element using configuration

Answer 14

count all electron in the last main shell