Atomic structure and the Periodic table

Question 1

What’s the shape of each orbital?

Answer 1

S-orbital = spherical
P-orbital = dumbbell
D-orbital = 4 leaf clover

Question 2

How many electrons in each shell ?

Answer 2

2,8,18,32

Question 3

What 2 elements don’t obey the Aufbau principle?

Answer 3

Chromium (puts 1 electron in 4s and then 1 in each 3d)
Copper (puts 1 electron in 4s and then puts 2 in each 3d)

Question 4

Is the 2nd ionisation energy more or less or equal to the 1st?

Answer 4

More

Question 5

Explain the trend in atomic radius going down a group ?

Answer 5

The atomic radius increases as you go down the group because more shells of electrons are added

Question 6

Explain the trend in atomic radius going across a period ?

Answer 6

It decreases because electrons are added to the same shell so there is an increased nil at charge

Question 7

Explain the trend in ionisation energy ?(example period 2)

Answer 7

Across the period, the nuclear charge increases, the shielding remains similar and the atomic radius decreases. As a result, the increased attraction of the electrons to the nucleus means more energy is required to remove an electron. HOWEVER between group 2 and 3, B outer electron is removed from a p-orbital which is a higher energy level so it requires less energy to remove. Also between group 5 and 6 , O outer electron is paired whereas N outer electron is not. So O outer electron experiences a greater repulsion and requires less energy to remive

Question 8

Explain the trend in boiling point for metals across a period?

Answer 8

• large metallic structure mean that the bonds are harder to overcome
• across a period, the number of delocalised electrons increases and so does the charge so there is a stronger force to overcome so there is a higher boiling point

Question 9

Explain the trend in the boiling point of non-metals across a period?

Answer 9

-simple covalent molecules have weak intermolecular/London forces
-small molecules (monoatomic) have the weakest forces and are easiest to overcome so they have the lowest boiling points.
-vise versa with large molecules (S8)