Question

Magnalium contains:
A. Aluminium + magnesium
B. Magnesium + copper
C. Magnesium + iron
D. Magnesium + silver

Answer 1

Hint: We know that magnalium is an alloy. An alloy is a combination of metal with another metal. Alloys have a metallic bonding character.

Complete answer:
- We know that magnalium is an alloy. An alloy is a combination of metal with another metal. Magnalium is an alloy of aluminium. It contains $95\% $ aluminium and $5\% $ magnesium. Magnalium also contains small amounts of copper, nickel and tin. Sometimes magnalium can have more up to $50\% $ magnesium. This makes magnalium brittle and it shows poor resistance to corrosion.
- Adding magnesium to aluminium increases the strength and hardness of aluminium.
- Magnalium alloy has a high strength, high corrosive resistance and low density than pure aluminium. Thus, magnalium is more workable. Welding of magnalium is easier than pure aluminium.
- Magnalium is used in making scientific instruments like balance beams and components of light instruments and metal mirrors.
- Thus, magnalium contains aluminium + magnesium.

Thus, the correct option is (A) aluminium + magnesium.

Additional Information:
Another alloy of aluminium and magnesium is known as birmabright. It contains $1 - 7\% $ magnesium, more than $1\% $ manganese and the remaining is aluminium. It is weldable and has a good corrosion resistance even in sea water. Thus, it is used in making light alloy boats.

Note:
Magnalium is used in making aircrafts and automobile parts. The magnalium alloy in its powdered form is highly flammable and thus, magnalium can be used to produce sparks. The reactivity of magnalium is higher than that of aluminium and thus, on burning magnalium forms hot and bright yellow sparks.