Understanding Atomic Structure and Periodic Trends

Bohr model

A model that was unable to account for complex emission spectra and why shells could only hold 2n^2 electrons.

Schrödinger's model

A model that treats electrons as a wave and as having wave-like properties.

Subshell

A division of electron shells that can contain orbitals.

Orbitals

Regions in an atom where there is a high probability of finding electrons.

Max. Electrons in s subshell

2

Max. Electrons in p subshell

6

Max. Electrons in d subshell

10

Max. Electrons in f subshell

14

Max. Electrons in shell 1

2

Max. Electrons in shell 2

8

Max. Electrons in shell 3

18

Max. Electrons in shell 4

32

Total number of energy levels in atoms

7

Effective Nuclear Charge (ENC)

The attraction force applied to the valence electrons.

Electronegativity

The atom's ability to attract shared electrons to itself.

Total number of orbitals in a shell

n^2

Total number of electrons per shell

2n^2

What does Pauli's exclusion principle state?

States that an orbital can hold no more than two electrons.

What does Hund's rule state?

States that when electrons occupy orbitals of equal energy, one electron enters each orbital before pairing.

First ionisation energy

The amount of energy required to remove an electron from an atom in its gaseous state.

Metallic character

The readiness to lose electrons.

Non-metallic character

The readiness to gain electrons.

Density of metals

Relatively high.

Malleability

The ability to be beaten into a sheet.

Conductivity

How well electrons can move through a substance.

Ductility

The ability to be drawn into wires.

Luster

The way a mineral reflects light from its surface.

Tensile strength

A measure of how much stress from pulling, or tension, a material can withstand before breaking.