Difference Between Beryllium and Aluminium

Key Difference – Beryllium vs Aluminium
 

Beryllium and Aluminium are two metallic elements in two different periods and groups of the periodic table. The key difference between Beryllium and Aluminium is that Beryllium is a molecule in the group II (atomic number = 4) whereas Aluminium is a group XIII element (atomic number = 13). They have different chemical properties, and they are unique to them. For example, if we consider their metallic properties, Beryllium is the lightest metal used in construction and Aluminium is the second largest metal used in the world after Iron.

What is Beryllium?

Beryllium (Be) is a chemical element with the atomic number 4, and the electronic configuration is 1s²2s². It is in group II and period 2 in the periodic table. It is the lightest member of alkaline earth family. Beryllium naturally occurs with other elements such as Bertrandite (Be₄Si₂O₇(OH)₂), Beryl (Al₂Be₃Si₆O₁₈), Chrysoberyl (Al₂BeO₄) and Phenakite (Be₂SiO₄). The abundance of beryllium in Earth’s surface is about 4-6 ppm, it is relatively low.

What is Aluminum?

Aluminum (Al) is an element from group XIII, period 3. Atomic number is 13 and electronic configuration is 1s²2s²2p⁶3s²3p¹. It has only one naturally occurring isotope aluminium-27. It naturally occurs in many different minerals and the abundance of aluminum in the Earth’s crust. Aluminum is a very important element in industrial applications. It is the second largest metallic element used in the world.

What is the difference between Beryllium and Aluminum?

Physical Properties:

Beryllium: Beryllium is a metallic element with a grayish-white surface; it is brittle and hard (density = 1.8 gcm^-3). It is the lightest metallic element that can be used in construction industry. Its melting point and boiling point are 1287°C (2349°F) and 2500°C (4500°F) respectively. Beryllium has a high heat capacity and good heat conductivity.

Beryllium has an interesting property related to x-rays penetration through the material. It is transparent to x-rays; in other words, x-rays can pass through Beryllium without being absorbed. For this reason, it is sometimes used to make the windows in x-ray machines.

Aluminium: Aluminium has silvery metallic luster with a slightly bluish tint. It is both ductile (the ability to make into a thin wire) and malleable (the ability to hammer or press permanently out of shape without breaking or cracking). Its melting point is 660°C (1220°F), and the boiling point is 2327-2450°C (4221-4442°F).The density of Aluminum is 2.708gcm^-3. Aluminum is an extremely good electrically conductor. It is a low-cost material, and engineers try to use Aluminum more frequently in electrical equipment.

Chemical Properties:

Beryllium: Beryllium reacts with acids and water producing hydrogen gas. It reacts with oxygen in the air and forms a protective oxide layer on the surface and prevents the metal from further reacting.

Aluminum: Aluminum slowly reacts with oxygen and forms a very thin, whitish coating on the metal. This oxide layer prevents the metal oxidizing further and rusting. Aluminum is fairly reactive metal; it reacts with hot acids and with alkalis too. For this reason, Aluminum is considered as an amphoteric element (reacts with both acids and alkalis). Also, it reacts quickly with hot water and the powdered form of Aluminum quickly catches fire when exposed to a flame.

Uses:

Beryllium: Beryllium is mostly used in alloys; most popularly with copper. It is also used in manufacturing telecommunication equipment, computers, and cellular phones.

Aluminum: Aluminum is used to produce packaging materials, electrical equipment, machinery, automobiles and in the construction industry. It is also used as a foil in packaging; this can be melted and reused or recycled.

 

Image Courtesy:

1. Electron shell 004 Beryllium – no label By Pumbaa (original work by Greg Robson) (File:Electron shell 004 Beryllium.svg) [CC BY-SA 2.0 uk], via Wikimedia Commons

2. Electron shell 013 Aluminum By Pumbaa derivative work: Materialscientist [CC BY-SA 2.0 uk], via Wikimedia Commons