quiz 5 iron element lesson 3 sec 3

1. Which of the following substances conduct electricity in the solid state as well as in the molten state?

• Alloys

• metal oxides

• Salts

• Iron ores

Processes that aim to increase the percentage of iron in the ore

• The crushing, the sintering

• The concentrating, the crushing

• The roasting, the concentrating

• The sintering, the roasting

Dressing of ore aims to all the following except …

• Decrease the ratio of impurities

• Changing the physical properties of iron ore

• Converting the different ore to red iron ore

• Reduce hematite to iron metal

Iron ore is changed to hematite by …

• Physical treatment

• Roasting

• Crushing

• Reduction

The opposite figure shows balls of

• Hematite ore resulting from crushing process

• Magnetite ore resulting from sintering process

• Limonite ore resulting from sintering process

• Siderite ore resulting from crushing process

.... is produced during roasting

• V₂O₅

• CO₂

• SO₂

• O₂

Brass and bronze are two decorative alloys that have been produced by man for thousands of years. Which period 4 transition metal do bronze and brass both contain?

• copper

• Cobalt

• Zinc

• Titanium

The ratio between atomic size of 2 elements used in substitutional alloy is …

• 1:2

• 1:3

• 1:1

• 1:4

Hematite is decreased by ... of limonite

• 4 Oxygen atom

• hydrated water

• 2 hydrogen atoms

• 3 iron atoms

What is the chemical formula of pyrite ore?

• FeCO₃

• FeS₂

• Fe₂O₃

• Fe₃O₄