What is the Difference Between Beryllium and Aluminium

Beryllium and aluminium are two metallic elements that with distinct properties, despite sharing several similarities. While both belong to the group of metals in the periodic table, their atomic structures and chemical behaviors set them apart.

What is the difference between beryllium and aluminium? Beryllium is a blue-grey element that is lighter than aluminium, whereas aluminium is a silvery-white element in group 13, period 3, and is heavier than beryllium.

Key Areas Covered

1. What is Beryllium
      – Definition, Properties
2. What is Aluminium
      – Definition, Properties 
3. Similarities Between Beryllium and Aluminium
      – Outline of Common Features
4. Difference Between Beryllium and Aluminium
      – Comparison of Key Differences
5. FAQ: Beryllium and Aluminium
      – Answers to Frequently Asked Questions

Key Terms

Beryllium, Aluminium, Metal

What is Beryllium

Beryllium is a blue-grey metal in group 2, period 2 of the periodic table. It has the atomic number 4 and an atomic mass of 9.012182 u. Its chemical symbol is Be. It readily loses both its valence electrons, forming a stable Be²+ cation. The small size of the Be²+ ion also allows it to form covalent bonds with certain elements. Many of the properties of beryllium are determined by this positively charged ion. When beryllium is exposed to air, the formation of a thin oxide layer can be observed. This protective layer aims to shield beryllium from further corrosion.

Beryllium and its compounds can be highly toxic if inhaled. Hence, it is advised to take safety precautions when handling this element and its compounds.

Beryllium is used in making aircraft components, missiles, and spacecraft because of its high strength-to-weight ratio. Beryllium is transparent to X-rays, so it is used in X-ray windows and other instruments. In nuclear applications, its ability to moderate neutrons makes it essential for reactor components.

What is Aluminium

Aluminium is a silvery-white metal with the chemical symbol Al and an atomic number of 13. Its density is 2.7 g/cm³. It is found in Group 13 on the periodic table and is the most abundant metallic element in the Earth’s crust. Aluminium is rarely found in its pure form due to its reactivity with other elements to form compounds, particularly with oxygen. When exposed to air, aluminium reacts with oxygen to form a thin layer of aluminium oxide on its surface, protecting it from further corrosion.

The most common oxidation state of aluminium is +3, leading it to lose three electrons in forming most of its compounds. However, aluminium can also exhibit +1 and +2 oxidation states, though less commonly. aluminium is amphoteric, meaning it reacts with both acids and bases. Under acidic conditions, aluminium acts as a metal and donates electrons, forming aluminium salts and hydrogen gas, while under basic conditions, it can act as a nonmetal and form a complex ion called aluminate (Al(OH)₄⁻).

Aluminium has many uses, especially in the construction industry. It is used to make kitchen utensils like pots and pans, laptops and electronic items, electrical wires, power lines, lightweight building frames, window frames, and roofings.

Similarities Between Beryllium and Aluminium

• Both are elements found in the periodic table.
• They are metallic elements.
• Beryllium and aluminium have relatively low melting points.

Difference Between Beryllium and Aluminium

Definition

• Beryllium (Be) is a lightweight, steel-gray metal with an atomic mass of 9.012182 u, while aluminium (Al) is a silvery-white metal with an atomic mass of approximately 26.98 u.

In Nature

• Beryllium is relatively rare in nature, whereas aluminium is the most abundant metal in the Earth’s crust.

Chemical Nature

• Beryllium belongs to Group 2 (alkaline earth metals) with an atomic number of 4. Aluminium belongs to Group 13 (boron group) with an atomic number of 13.

Toxicity

• Beryllium dust is highly toxic and can cause serious health problems with long-term exposure. Aluminium is generally considered safe for most applications.

Density

• Aluminium is denser than beryllium.

Oxidation State

• Beryllium’s most common oxidation state is +2, while aluminium’s most common oxidation state is +3.

Conclusion

Beryllium, with its lighter weight, high strength-to-weight ratio, and toxicity, finds utility in aerospace, nuclear applications, and X-ray technology. Aluminium, abundant in nature and less toxic, serves diverse roles in construction, electronics, and household items. This is the main difference between beryllium and aluminium.

FAQ: Beryllium and Aluminium

1. Which element is lighter, beryllium or aluminium?

Beryllium is lighter than aluminium. This is because beryllium has a lower atomic mass and density compared to aluminium.

2. What is more electropositive, beryllium or aluminium?

Beryllium is more electropositive than aluminium. This difference in electropositivity is due to the position of each element in the periodic table and their atomic structures.  As a group 2 metal, beryllium exhibits a higher tendency to lose electrons and form positive ions compared to aluminium, which is a group 13 metal.

3. Why does Al lose electrons?

Aluminium (Al) typically loses electrons to achieve a stable electron configuration. In its neutral state, aluminium has three electrons in its outermost shell, but its outermost shell can hold up to eight electrons. By losing its three valence electrons, aluminium achieves a full outer shell, which is more stable according to the octet rule.

4. Is berillium non-toxic?

No. Beryllium is a toxic element. When inhaled or as a skin irritant, it can cause harmful effects. It may result in dermatitis, acute pneumonitis, and chronic pulmonary disease.

5. What are the carbides of beryllium and aluminium?

Beryllium carbide (Be₂C) and aluminium carbide (Al₄C₃) are the carbides formed by beryllium and aluminium, respectively. These compounds are characterized by their strong covalent bonding between the carbon and metal atoms, resulting in stable structures.

Reference:

1. “Beryllium.” Encyclopedia Britannica.  
2. “Aluminium.” Encyclopedia Britannica.  

Image Courtesy:

1. “Aluminium-4” By Alchemist-hp = Alchemist-hp (pse-mendelejew.de) – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Be-140g” By Unknown author – http://images-of-elements.com/aluminium.php (CC BY 3.0) via Commons Wikimedia