Electronic Structure & Orbitals

Question 1

What are shells?

Answer 1

• known as energy levels
• the shell number is also known as the principle quantum number
• energy increases as shell number increases

Question 2

What are atomic orbitals?

Answer 2

A region around the nucleus that can hold up to 2 electrons, with opposite spins.

Question 3

What are the key features of an s-orbital?

Answer 3

• spherical
• holds up to 2 electrons

Question 4

What are the key features of a p-orbital?

Answer 4

• dumb-bell shaped
• 3 orbitals
• hold up to 6 electrons

Question 5

What are the key features of a d and f-orbital?

Answer 5

D-orbital:
- five orbitals
- hold up to 10 electrons

F-orbital:
- seven orbitals
- hold up to 14 electrons

Question 6

Why is the 4s sub shell filled before the 3d sub shell?

Answer 6

• the highest energy level in the third shell overlaps with the lowest energy level in the fourth shell.
• the 3d sub shell is at a higher energy level than the 4s sub shell
• so the 4s sub shell fils up first