alloys and uses of metals

A metal is hit with a hammer. If it dents and changes shape easily it is..

• Malleable

• Hard

• Ductile

• Brittle

Pure metals conduct electricity and can be hammered into different shapes. Why are metals sometimes used as alloys?

• Alloys are cheaper than the metals they are made from.

• Alloys are easier to hammer into different shapes.

• Alloys are harder and keep their shape better.

• Alloys conduct electricity better.

An alloy always contains...

• A mixture of types of atom, at least one of which is a metal

• A mixture of types of atom, all of which must be metals

• just one type of atom, arranged in neat rows

• two or more types of atom, chemically bonded together

Brass is a mixture of

• copper and zinc

• silver and gold

• zinc and iron

• carbon and copper

This is the structure of alloys.

• TRUE

• FALSE

Which of the following is an alloy?

• Aluminium

• Brass

• Air

• Sodium chloride

Which of the following alloy is made up of copper and tin?

• bronze

• brass

• stainless steel

• pewter

Why is alloy hard and strong?

• due to strong metallic bond between the elements

• atoms are regularly arranged and can act as lubricant

• it is made up of mixture of metals

• due to mismatched size of atoms and these atoms cant slide past each other

Which of the following equation is correct when metals react with acids?

• metal + acid $\rightarrow$ salt + hydrogen

• metal + acid $\rightarrow$ metal hydroxide + hydrogen

• metal + acid $\rightarrow$ metal oxide + hydrogen

• metal + acid $\rightarrow$ metal oxide

Which metal would be suitable for all of the following uses?
# Making aircraft bodies
# Making food containers
# Making overhead power cables

• aluminium

• mild steel

• gold

• pure iron