NCERT Exemplar solutions for Science [English] Class 10 chapter 3 - Metals and Non-metals [Latest edition]

Which of the following property is generally not shown by metals?

The ability of metals to be drawn into thin wire is known as

Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?

1. Good thermal conductivity
2. Good electrical conductivity
3. Ductility
4.  High melting point

Which one of the following metals do not react with cold as well as hot water?

Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?

What happens when calcium is treated with water?

1. It does not react with water
2. It reacts violently with water
3. It reacts less violently with water
4. Bubbles of hydrogen gas formed stick to the surface of calcium

Generally metals react with acids to give salt and hydrogen gas. Which of the following acids does not give hydrogen gas on reacting with metals (except Mn and Mg)?

The composition of aqua-regia is

Which of the following are not ionic compounds?

1. KCl
2. HCl
3. CCl₄
4. NaCl

Which one of the following properties is not generally exhibited by ionic compounds?

Which of the following metals exist in their native state in nature?

1. Cu
2. Au
3. Zn
4. Ag

Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?

1. Au
2. Cu
3. Na
4. K

Silver articles become black on prolonged exposure to air. This is due to the formation of

Galvanisation is a method of protecting iron from rusting by coating with a thin layer of

Stainless steel is very useful material for our life. In stainless steel, iron is mixed with

If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of

Generally, metals are solid in nature. Which one of the following metals is found in liquid state at room temperature?

Which of the following metals are obtained by electrolysis of their chlorides in molten state?

1. Na
2. Ca
3. Fe
4. Cu

Generally, non-metals are not lustrous. Which of the following non-metal is lustrous?

Which one of the following four metals would be displaced from the solution of its salts by other three metals?

2 mL each of concentrated HCl, HNO₃ and a mixture of concentrated HCl and concentrated HNO₃ in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be

An alloy is

An electrolytic cell consists of

1. positively charged cathode
2. negatively charged anode
3. positively charged anode
4. negatively charged cathode

During electrolytic refining of zinc, it gets

An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following

Alloys are homogeneous mixtures of a metal with a metal or nonmetal. Which among the following alloys contain non-metal as one of its constituents?

Which among the following statements is incorrect for magnesium metal?

Which among the following alloys contain mercury as one of its constituents?

Reaction between X and Y, forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z?

The electronic configurations of three elements X, Y and Z are X – 2, 8; Y – 2, 8, 7 and Z – 2, 8, 2. Which of the following is correct?

Although metals form basic oxides, which of the following metals form an amphoteric oxide?

Generally, non-metals are not conductors of electricity. Which of the following is a good conductor of electricity?

Electrical wires have a coating of an insulting material. The material, generally used is

Which of the following non-metals is a liquid?

Which of the following can undergo a chemical reaction?

Which one of the following figures correctly describes the process of electrolytic refining?

Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.

During extraction of metals, electolytic refining is used to obtain pure metals.
(a) Which material will be used as anode and cathode for refining of silver metal by this process?
(b) Suggest a suitable electrolyte also.
(c) In this electrolytic cell, where do we get pure silver after passing electric current?

Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?

Compound X and aluminium are used to join railway tracks.

1. Identify the compound X
2. Name the reaction
3. Write down its reaction.

When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z which easily catches fire. Identify X, Y and Z and also write the reaction involved.

The following reaction takes place when aluminium powder is heated with MnO₂

`3"MnO"_2("s") + 4"Al"("s") -> 3"Mn"("l") + 2"Al"_2"O"_3("l") + "Heat"`

1. Is aluminium getting reduced?
2. Is MnO₂ getting oxidised?

Give the formulae of the stable binary compounds that would be formed by the combination of following pairs of elements.

1.  Mg and N₂
2.  Li and O₂
3.  Al and Cl₂
4.  K and O₂

What happens when

1. ZnCO₃ is heated in the absence of oxygen?
2. a mixture of Cu₂O and Cu₂S is heated?

A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming

1. Identify A, B and C
2. To which Group of Periodic Table does A belong?

Give the reaction involved during extraction of zinc from its ore by

1. roasting of zinc ore
2. calcination of zinc ore

A non-metal A which is the largest constituent of air, when heated with H₂ in 1:3 ratio in the presence of catalyst (Fe) gives a gas B. On heating with O₂ it gives an oxide C. If this oxide is passed into water in the presence of air it gives an acid D which acts as a strong oxidising agent.

1. Identify A, B, C and D
2. To which group of periodic table does this non-metal belong?

Explain the following

1. Reactivity of Al decreases if it is dipped in HNO₃
2. Carbon cannot reduce the oxides of Na or Mg
3. NaCl is not a conductor of electricity in solid state whereas it does conduct electricity in aqueous solution as well as in molten state
4. Iron articles are galvanised.
5. Metals like Na, K, Ca and Mg are never found in their free state in nature.

1.  Given below are the steps for extraction of copper from its ore. Write the reaction involved.
   1.  Roasting of copper (I) sulphide
   2. Reduction of copper (I) oxide with copper (I) sulphide.
   3. Electrolytic refining
2. Draw a neat and well labelled diagram for electrolytic refining of copper

An element A burns with golden flame in air. It reacts with another element B, atomic number 17 to give a product C. An aqueous solution of product C on electrolysis gives a compound D and liberates hydrogen. Identify A, B, C and D. Also write down the equations for the reactions involved.