Electron Configuration of Atoms + Periodic Relationship Among Elements

Pauli Exclusion Principle

No two electrons in an atom can have the same set of quantum numbers.

Hund’s Rule

The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

AUFBAU Principle

As protons are added one by one to the nucleus to build up each element, electrons are similarly added to the atomic orbitals.

Diamagnetic

Magnetic Properties of Atoms:

All electrons are paired.

Paramagnetic

Magnetic Properties of Atoms:

There is at least one unpaired electron.

1A - 7A

In what groups can you find the Representative Elements?

8A

In what groups can you find the Noble Gases?

1B - 8B (except 2B)

In what groups can you find the Transition Metals?

Where can you find 2B?

6

In what period can you find the Lanthanides?

7

In what period can you find the Actinides?

Core Electrons

Electrons with completely filled subshells.

Valence Electrons

Electrons located in the outermost shell of an atom (incomplete).

Cations

Positively Charged Electrons

Anions

Negatively Charged Electrons

Isoelectronic Species

Atoms, ions, or molecules that have the same number of electrons and the same electron configuration.

• F^-,

• O^2-

• N^3-

• Na⁺

• Al³⁺

What elements are the Isoelectronic Species?