Shells and Orbitals

Question 1

What is the principle quantum number?

Answer 1

• Represents relative overall energy of each orbital, increasing with distance from nucleus
• Orbital sets with same n value are referred to as electron shells or energy levels

Question 2

What is a shell?

Answer 2

• Atomic orbital groups with same principal quantum number

Principal quantum number, n, is a number representing the relative overall energy of each orbital, which increases with distance from the nucleus. The sets of orbitals with the same n value are referred to as electron shells or energy levels.

Question 3

What is the principle quantum number also known as?

Answer 3

Main energy level

Question 4

How is it now thought electron shells are structured?

Answer 4

Made of atomic orbitals, each holding a maximum of 2 electrons with opposite spins

Question 5

What is an orbital?

Answer 5

Region of space where electrons may be found

Question 6

What are the four different types of orbitals?

Answer 6

s, p, d, and f

Question 7

What is the shape of an s orbital?

Answer 7

Spherical

Question 8

Which shells have s-orbitals?

Answer 8

From n = 1 upwards, so each one

Question 9

What shape are p-orbitals?

Answer 9

3D dumbbell

Question 10

Which shells have p-orbitals?

Answer 10

From n = 2 upwards, each containing 3 p-orbitals

Question 11

How are the 3 p-orbitals arranged?

Answer 11

All at right angles to one another

Question 12

How many p-electrons can be held in an orbital?

Answer 12

6

Question 13

Which shells have d-orbitals?

Answer 13

From n = 3 upwards, each containing 5 d-orbitals

Question 14

How many d-electrons can be held in an orbital?

Answer 14

10

Question 15

Which shells have f-orbitals?

Answer 15

From n = 4 upwards, each containing 7 f-orbitals

Question 16

How many f-electrons can be held in an orbital?

Answer 16

14

Question 17

Why do chemists use ‘electron boxes’ to represent electrons in orbitals?

Answer 17

• Have different types and shapes
• Represents individual orbitals

Question 18

How many electrons can be held in each ‘electron box’?

Answer 18

2

Question 19

Why don’t electrons in the same orbital repel each other?

Answer 19

Because they spin in opposite directions, up or down.