Aluminium

POST-TRANSITION METAL

Bohr Model: Electrons arranged in energy shells around the nucleus.

Aluminium (or aluminum; see different endings) is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal. Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal, in the Earth's crust.

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Quick Facts

Atomic Number 13

Period 3

Group 13

Phase Solid

Appearance silvery gray metallic

About Post-Transition Metals

Transition metals are elements with partially filled d-orbitals. They are hard, have high melting points, and often form colored compounds.

History

Discovered By N/A

Named By Humphry Davy

Physical Properties

Atomic Mass 26.98153857

Density 2.7 g/L

Molar Heat 24.2 J/(mol·K)

Phase Transition (Melting & Boiling Points)

Aluminium melts at 933.47 K and boils at 2743 K.

Atomic Properties

Electron Config [Ne] 3s2 3p1

Electronegativity 1.61

Electron Affinity 41.762 kJ/mol

Ionization Energy 577.5 kJ/mol

Orbital Filling Diagram

This diagram visualizes electron configuration according to the Aufbau principle and Hund's rule. Boxes represent orbitals (s, p, d, f), while arrows indicate electrons with spin up or down. Electrons fill lower energy levels first and occupy orbitals singly before pairing.

Photograph

Source: Wikipedia

External Resources

Wikipedia PubChem Royal Society of Chemistry Periodic Videos (YouTube)

Study Guide

Atomic Number

The number of protons in the nucleus, which defines the element.

Atomic Mass

The average mass of an atom, including protons and neutrons.

Electronegativity

A measure of how strongly an atom attracts electrons in a bond.

Ionization Energy

The energy required to remove an electron from an atom.

Electron Config

The arrangement of electrons in the atom's energy shells.