ALLOY

‘Bronze is harder than copper’. Which of the following is the best to explain the statement?

• Atoms in bronze are arranged closely packed and less empty spaces.

• Layers of atoms in bronze are not easily slide over each other.

• Atomic size of copper and tin is different.

• Bronze is a mixture of copper and tin

What is the composition of brass?

• 30% tin and 70% copper

• 10% tin and 90% copper

• 30% zinc and 70% copper

• 10% zinc and 90% copper

Which of the following statements below is true?

• Copper is more ductile than brass

• Brass is more malleable than copper

• Iron is shinier than stainless steel

• Iron is more resistant to corrosion than steel

An industrial product is made by adding chromium and carbon to iron. The product produced is

I. more malleable than iron

II. more resistant to corrosion than iron

III. is shinier than iron

IV. is harder than iron

• II and IV

• I, II and III

• II, III and IV

• I, II, II and IV

Which of the following mixture forms a light and strong alloy to make the body of a speeding boat?

• iron and carbon

• Aluminium and copper

• Copper and nickel

• Tin and lead

Alloying can harden the metals because

• the foreign atoms can prevent layers of atoms from sliding over each other

• the foreign atoms produce stronger attractive forces between the metal atoms

• the foreign atoms are stronger and harder

• the foreign atoms increase the energy of the metal atoms

Which of the following characteristics belong to pure metals?

I. Ductile

II. Malleable

III. Brittle

IV. Good conductor of electricity

• I and II

• I and IV

• I, II and IV

• I, II, III and IV

Which of the following properties does not belong to an alloy as compared to its pure metal?

• Stronger

• More corrosion resistant

• Harder

• More malleable

Diagram above shows the arrangement of atoms in brass. Which of the following could be atoms X and Y?

• X : Copper Y: Tin

• X: Zinc Y: Copper

• X: Iron Y: Carbon

• X: Copper Y: Zinc