Atoms & Orbitals

Question 1

What are the different types of orbitals?

Answer 1

s (smiley), p (potatoes), d (don’t), f (frown)

Question 2

What’s the maximum number of electrons each sublevel can contain?

Answer 2

s - 2
p - 6
d - 10
f - 14

Question 3

Which shells contains which types of orbitals?

Answer 3

Shell 1 - Contains 1 s orbital.
Shell 2 - Contains 1 s orbital and 3 p orbitals.
Shell 3 - Contains 1 s orbital, 3 p orbitals and 5 d orbitals.
Shell 4 - Contains 1 s orbital, 3 p orbitals, 5 d orbitals (e.g. a group of equivalent orbitals is called a subshell) and 7 f orbitals.

Question 4

What is the Pauli exclusion principle?

Answer 4

An orbital can hold a maximum of 2 electrons.

Question 5

What are the energies of the orbitals in increasing order?

Answer 5

1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 4d → 4f

Question 6

Describe the orbitals energy levels in relation to the nucleus.

Answer 6

Orbitals that are closer to the nucleus have lower energies whereas high energy orbitals are further away from the nucleus in space.

One exception to the rule is that the 4s orbital in shell 4 has a lower reactivity that the 3d orbital in shell 3.

Question 7

Define the Aufbau principle.

Answer 7

The Aufbau principle states that in the ground state of an atom or ion, electrons fill subshells of the lowest available energy, then they fill subshells of higher energy.

Question 8

What is lithium’s electronic configuration?

Answer 8

1s² 2s¹

Question 9

What is Oxygen’s electronic configuration?

Answer 9

1s² 2s² 2p⁴

Question 10

What is carbon’s electronic configuration?

Answer 10

1s² 2s² 2p²

Question 11

What is calcium’s electronic configuration?

Answer 11

1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

Question 12

What is the electronic configuration of silver?

Answer 12

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁹

Question 13

What does degenerate mean?

Answer 13

When all the orbitals in a subshell have the same energy (in shell 2 the 3 2p orbitals have the same energy).

Question 14

Describe Hund’s rule.

Answer 14

• In a sublevel, each orbital is singly occupied
  before it is doubly occupied. The electrons enter
  an empty orbital before pairing up.
• The electrons present in singly occupied
  orbitals possess identical spin. The electrons
  repel each other as they are negatively
  charged.

Question 15

What are valence electrons?

Answer 15

Electrons that are held furthest away from the nucleus and are key for reactivity of an atom or ion (involved when ions and compounds are formed from atoms).

Question 16

Define ionization energy?

Answer 16

The amount of energy required to remove an electron from an atom.

Question 17

How does ionization energy change across a period.

Answer 17

It increases. As you move across a period increasing amounts of energy are required to remove the first valence electron (i.e. it gets harder to do this). Electrons are easier to remove from atoms to the left of the periodic table (so they form cations (+)) compared to those on the right.

Question 18

Which atoms are the most stable?

Answer 18

The one’s that have full valence shells.

Question 19

What is the octet rule?

Answer 19

Main-group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.