Unit 1-Electronic Configurations And The Periodic table

Question 1

What is the Aufbau principle?

Answer 1

Orbitals are filled in order of increasing energy. 1s before 2s

Question 2

What is the order of orbital filling from 1s to 4d?

Answer 2

1s 2s 2p 3s 3p 4s 3d 4p 4d

Question 3

What is the Pauli exclusion principle?

Answer 3

This states that an orbital cannot contain more than two electrons and they must have opposite spins.

Question 4

What is Hund’s rule of maximum multiplicity?

Answer 4

Electrons fill each degenerate orbital singly with spins parallel before pairing occurs.

Question 5

What are the 2 types of notation used to represent the electron configurations of elements?

Answer 5

Spectroscopic notation and orbital box notation

Question 6

What the spectroscopic notation for a lithium atom?

Answer 6

1s2 2s1

Question 7

Which element has atoms with [Ar]4s1?

Answer 7

Potassium

Question 8

How many electrons are there in the 2p sub-shell of the oxygen atom?

Answer 8

4

Question 9

Which number would complete this spectroscopic notation for a nitrogen atom?

1s2 2s2 2p?

Answer 9

1s2 2s2 2p3

Question 10

Carbon has two unpaired electrons. How many unpaired electrons would boron have?

Answer 10

1

Question 11

What is the spectroscopic notation of a lithium ion?

Answer 11

1s2

Question 12

Which element does this orbital box notation represent?

Answer 12

Hydrogen

Question 13

Which element does this orbital box notation represent?

Answer 13

Fluorine

Question 14

How would lithium be represented as orbital box notation?

Answer 14

Question 15

How would oxygen be represented as orbital box notation?

Answer 15

Question 16

Which areas represent elements which have s, p, d or f electrons in the outermost sub-shell?

Answer 16

Question 17

1. Which element group appears at the four peaks?
2. Would the ionisation be easy or difficult?
3. Are these elements reactive or unreactive?
4. How many electrons in the outer shell?

Answer 17

1. These are group 0, noble gases.
2. Difficult as it is a high value.
3. Unreactive noble gases.
4. All are full, usually with 8 electrons

Question 18

Why is there a slight dip in first ionisation energy from beryllium to boron?

Answer 18

Beryllium is 1s2 2s2 and boron is 1s2 2s2 2p1

Beryllium has a full sub-shell and is more stable. Boron has a single 2p electron and is less stable.

Question 19

Why is there a dip in first ionisation energy in the middle of the p-block from nitrogen to oxygen?

Answer 19

Nitrogen is 1s2 2s2 2p3 and oxygen is 1s2 2s2 2p4

Half filled sub-shells are relatively stable and it is easier to remove the fourth ‘p’ electron from the 2p shell of oxygen.