Materials Metals and Non Metals Test - 15

Metals generally react with acids to liberate hydrogen gas. However, metals like copper, gold, and silver do not react with acids.

The correct answer is B.

Copper is less reactive. It does not react with dilute hydrochloric acid even on heating. However, it reacts with sulphuric acid easily.

The correct answer is B.

Mercury is the only metal which is found in the liquid state at room temperature. It is a good conductor of heat and is extensively used in thermometers. Gold is lustrous and malleable. Hence, it is used in making jewellery.

The correct answer is A.

Zinc displaces copper from its salt solution, but copper cannot displace zinc from its salt solution. Therefore, zinc is more reactive than copper.

∴ Reactivity of Cu < Reactivity of Zn…………. (i)

Zinc can also displace iron from its salt solution. Therefore, zinc is more reactive than iron.

∴ Reactivity of Fe < Reactivity of Zn………….. (ii)

Iron can displace copper from its salt solution, but copper cannot displace iron from its salt solution. Therefore, iron is more reactive than copper.

∴ Reactivity of Cu < Reactivity of Fe…………… (iii)

On combining equations (i), (ii), and (iii), the correct increasing order of reactivity of iron, copper, and zinc is Cu < Fe < Zn.

Hence, the correct answer is option B.

Sulphur is a non-metal. Non-metals are brittle (not ductile) and poor conductors of heat and electricity. Hence, sulphur cannot be used for making electric wires.

The correct answer is D.

Copper undergoes corrosion. If exposed to air for long, a dull green coating is formed on its surface. This green coating is a mixture of copper hydroxide and carbonate.

The correct answer is B.

When struck hard, non-metals do not produce a sound. Hence, they are not sonorous.

The correct answer is C.

Most metals are ductile, but exceptions like mercury, sodium, and potassium do exist. These metals cannot be drawn into wires. Sodium and potassium are soft metals, which can be cut with a knife. Mercury is the only metal which is found in the liquid state at room temperature.

The correct answer is C.

Air has oxygen in it. Most metals react with oxygen to produce oxides that occur in the highest amounts. For example, magnesium reacts with oxygen to produce magnesium oxide. The chemical equation involved in the reaction can be represented as:

Magnesium (Mg) + Oxygen (O₂, from air) → Magnesium oxide (MgO)

The correct answer is A.

Coal is made of carbon, which is a non-metal. Non-metals have a dull appearance. They are not shiny as metals. Hence, coal has a dull appearance.

The correct answer is B.

Metals are usually hard. However, there are a few exceptions such as metals like sodium are potassium, which are soft and can be cut with a knife. On the other hand, mercury is the only metal, which is found in the liquid state at room temperature.

The correct answer is A.

Zinc is a metal, which can be beaten into sheets. The property of metals by which they can be beaten into sheets is called malleability.

The correct answer is A.

Metals can be beaten into thin sheets. This property of metals is called malleability. Copper is a metal, which is malleable in nature. Hence, it can be beaten into thin sheets.

The correct answer is D.

Aluminium is a metal. Generally, metals are malleable. Aluminium can be beaten into thin sheets. Therefore, it is used for wrapping food items.

The correct answer is B.

Metals react with acids to produce metal salts and hydrogen gas. Magnesium is a metal. Hence, it reacts with sulphuric acid to produce magnesium sulphate (metal salt) and hydrogen gas.

The correct answer is D.