Question

Between the atomic numbers $1,11,13$and $31$ which of these is used for making alloys for aeroplanes? Explain.

Answer 1

Part 1: Alloy: It is a substance that is formed from mixing two metals or a metal and a non-metal. Example: Brass is an alloy of Copper $\mathrm{Cu}$ and Zinc $\mathrm{Zn}$.

• The elements with atomic numbers $1,11,13$and $31$ are Hydrogen $\mathrm{H}$, Sodium $\mathrm{Na}$, Aluminium $\mathrm{Al}$ and Gallium $\mathrm{Ga}$, respectively.
• Among these elements, Aluminium is used for making alloys for aeroplanes. It is present in the group $13$ of the periodic table.

Part 2: Aluminium is used in making aeroplanes:

1. Aluminium is the most abundant metal found in the Earth's crust.
2. It is a strong metal and highly resistant to corrosion which guarantees the safety of the aeroplane.
3. Compared to other alloys, it is light in weight and thus permits aeroplanes to carry greater weight or become more fuel-efficient.
4. Also, it is highly ductile and malleable.

• Duralumin is an alloy made from Aluminium, Magnesium $\mathrm{Mg}$, Copper $\mathrm{Cu}$, and Manganese $\mathrm{Mn}$ used in the aircraft industry.
• Aluminium is preferred in alloy form because pure Aluminium loses its strength at high temperatures.

Therefore, the element with atomic number $13$ is used for making alloys for aeroplanes.