Please refer to Metals and Non-Metals Class 10 Science Exam Questions provided below. These questions and answers for Class 10 Science have been designed based on the past trend of questions and important topics in your class 10 Science books. You should go through all Class 10 Science Important Questions provided by our teachers which will help you to get more marks in upcoming exams.
Class 10 Science Exam Questions Metals and Non-Metals
Class 10 Science students should read and understand the important questions and answers provided below for Metals and Non-Metals which will help them to understand all important and difficult topics.
Very Short Answers Type Questions
Question: Which gas is generally liberated when a dilutesolution of hydrochloric acid reacts with an active metal?
Answer: Generally, hydrogen gas is liberated when dilute solution of hydrochloric acid reacts with active metals.
Question: From amongst the metals sodium, calcium, aluminium, copper and magnesium, name the metal
(i) which reacts with water only on boiling and
(ii) another which does not react even with steam.
Answer: (i) Aluminium is the metal which reacts with water only on boiling (i.e., it reacts with steam).
(ii) Copper metal does not react even with steam due to its low reactivity.
Question: Arrange the following metals in a decreasing order of activity :
Answer: The decreasing order of activity is
K >Na> Cu >Ag
Question: Explain the meanings of malleable and ductile.
Answer : Malleable : Substances that can be converted into thin sheets by beating are called malleable. Most of the metals are malleable. Gold and silver are most malleable metals.
Ductile : Substances that can be drawn into thin wires are called ductile. Most of the metals are ductile. Gold is the most ductile metal.
Question: Silver articles become black when kept in open for some time, whereas copper vessels lose their shiny brown surfaces and gain a green coat when kept in open. Name the substances present in air with which these metals react and write the name of the products formed.
Answer : Silver articles become black when kept in open for some time, whereas copper vessel lose their shiny brown surfaces and gain a green coat when kept in open because silver articles reacts with sulphide compounds such as hydrogen sulphide present in the air to form silver sulphide (Ag2S) whereas copper reacts slowly with CO2 and water present in the air to form green coating of mixture of copper carbonate and copper hydroxide.
Question: A piece of granulated Zn was dropped into copper sulphate solution. Write down the colour change that you will observe.
Answer : When a piece of granulated Zn was dropped into copper sulphate solution, blue colour solution become colourless, reddish brown Cu gets deposited.
Question: Name one metal which has a low melting point.
Answer : Cesium.
Question: What name is given to those metal oxides which show basic as well as acidic behaviour ?
Answer : Amphoteric oxides.
Question: Name two metals which form amphoteric oxides.
Answer : Aluminium and zinc.
Question: How are covalent bonds formed ?
Answer : Covalent bonds are formed by the sharing of electrons between atoms. By sharing their outermost valence electrons, atoms can fill up their outer electron shell and gain stability.
Question: Give an example of a metal which
(a) is a liquid at room temperature.
(b) can be easily cut with a knife.
(c) is the best conductor of heat.
(d) is a poor conductor of heat.
Answer : (a) Metal that exists in liquid state at room temperature → Mercury
(b) Metal that can be easily cut with a knife → Sodium, Potassium
(c) Metal that is the best conductor of heat → Silver, Gold
(d) Metals that are poor conductors of heat → Mercury and lead
Question: Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Answer : Copper does not react with cold water, hot water, or steam. However, iron reacts with steam. If the hot water tanks are made of steel (an alloy of iron), then iron would react vigorously with the steam formed from hot water.
That is why copper is used to make hot water tanks and not steel.
Question: In the formation of a compound XY2 atom X gives one electron to each Y atom. What is the nature of bond in XY2 ? Give two properties of XY2.
Answer : XY2 has ionic bonds. XY2 would conduct electricity when dissolved in water and XY2 would have high melting and boiling point.
Question: An element ‘A’ has two electrons in the outermost shell of its atom and combines with an element ‘B’ having seven electrons in the outermost shell, forming the compound AB2. The compound when dissolved in water conducts electric current. Giving reasons, state the nature of chemical bond in the compound.
Answer : AB2 forms ionic bonds because an aqueous solution of an ionic compound conducts electricity because there are plenty of free ions in the solution which are able to conduct electric current.
Question: What happens when a copper rod is placed in silver nitrate solution ?
Answer : Copper displaces silver as it is more reactive. A blue coloured solution will be formed and grey coloured solution will be deposited at the bottom of container.
Question: Aluminium strips were placed in a solution of copper sulphate. After one hour, it was observed that the colour of solution changes. What will be the colour of the solution ? Give reasons.
Answer : Aluminium will displace Cu from copper sulphate solution. As a result, the solution will be colourless.
Short Answers Type Questions
Question: (a) Name a metal for each case :
(i) It does not react with cold as well as
hot water but reacts with steam.
(ii) It does not react with any physical state of water.
(b) When calcium metal is added to water the gas evolved does not catch Are but the same gas evolved on adding sodium metal to water catches Are. Why is it so?
Answer: (a) (i) Iron metal does not react with cold as well as hot water but it reacts with steam.
3Fe(s) + 4H2O(g)→ Fe3O4(s) + 4H2(g)↑
(ii) Gold does not react with cold water, hot water and not even with steam.
(b) When calcium metal is added to water the hydrogen gas evolved, does not catch Are because the reaction of calcium with water is less violent and the heat evolved is not sufficient for the hydrogen gas to catch are. But the same gas evolved on adding sodium metal to water, catches are because the reaction is very violent and highly exothermic and the heat evolved is sufficient for hydrogen gas to catch are.
Question: Using the electronic configurations, explain how magnesium atom combines with oxygen atom to form magnesium oxide by transfer of electrons.
Question: (a) Give two methods to prevent the rusting of iron.
(b) Name the ores of the following metals:
(i) mercury, and
(a) (i) Painting (ii) Galvanisation
(b) (i) Cinnabar (ii) Zinc Blende
Question: Write chemical equations that shows aluminium oxide reacts with acid as well as base.
Answer. AI2O3 + 6HCI → 2AICI3 + H2O
AI2O3 + 2NaOH → 2NaAIO2 + H2O
Question: Elements magnesium and oxygen respectively belong to group 2 and group 16 of the Modern Periodic Table. If the atomic numbers of magnesium and oxygen are 12 and 8 respectively, draw their electronic configurations and show the process of formation of their compound by transfer of electrons.
Question: (a) Show the formation of Na2O by the transfer of electrons between the combining atoms.
(b) Why are ionic compounds usually hard?
(c) How is it that ionic compounds in the solid state do not conduct electricity and they do so when in molten state?
Answer: (a) e formation of Na2O can be represented as
(b) Ionic compounds are usually hard due to strong forces of attraction between oppositely charged ions.
(c) Ionic compounds in the solid state do not conduct electricity because movement of ions in solid state is not possible due to the rigid structure. But they conduct electricity in the molten state as the electrostatic forces of attraction between oppositely charged ions are overcome by heat and ions become free to move.
Question: Name two metals which react violently with cold water. Write any three observations you would make when such a metal is dropped into water. How would you identify the gas evolved, if any, during the reaction?
Answer: Sodium and potassium react with cold water violently.
When these metals are dropped into water then following changes are observed :
(i) Bubbles come out of water due to the evolution of a gas.
(ii) This gas catches Are immediately.
(iii) e beaker becomes hot as the reaction is highly exothermic.
When a burning matchstick is brought near this gas (hydrogen) then it burns explosively with a ‘pop’ sound.
Question: Explain how the following metals are obtained from their compounds by the reduction process :
(i) Metal M which is in the middle of the reactivity series.
(ii) Metal N which is high up in the reactivity series. Give one example of each type.
Answer: (i) Those metals (M) which have moderate reactivity such as zinc, lead, iron, copper, etc.
are obtained by the reduction of their oxides by reducing agents such as carbon or aluminium
(ii) Those metals (N) which are high up in the reactivity series are extracted by electrolytic reduction method.
e.g., sodium is obtained by the electrolysis of its molten chloride. e sodium metal is deposited at the cathode, whereas chlorine is liberated at the anode.
Question: What are amphoteric oxides ? Give an example. Write balanced chemical equations to justify your answer.
Answer : Those oxides which behave as both acidic and basic oxides are called amphoteric oxides.
Example : Al2O3 (Alumina)
(a) Carbonate and sulphide ores are usually converted into oxides during the process of extraction because obtaining a metal from its metal oxide is much easier than from metal carbonates and sulphides.
(b) Aluminium is highly reactive metal still it is widely used in making cooking utensils because it reacts with O2 present in air to form aluminium oxide that forms a protective layer and protects the metal from corrosion.
Question: Name a metal of medium reactivity and write three main steps in the extraction of this metal from its sulphide ore.
Answer : Zinc
The steps inolved in extraction of zinc from zinc sulphide are :
(a) Roasting of sulphide ore in the presence of air to convert it into metal oxide.
(b) Reduction of metal oxide with carbon to get the free metal.
ZnO(s) + C(s) → Zn(s) + CO(g)
Zinc oxide Carbon Zinc Carbon-monoxide
(c) Refining of impure metal to get pure metal.
Question: Given below are the steps for the extraction of copper from its ore. Write the chemical equation of there actions involved in each case.
(a) Roasting of copper(I) sulphide.
(b) Reduction of copper(I) oxide from copper(I) sulphide
(c) Electrolytic refining.
Question: Explain the following :
(a) Sodium chloride is an ionic compound which does not conduct electricity in solid state where as it does conduct electricity in molten state as well as in aqueous solution.
(b) Reactivity of aluminium decrease if it is dipped in nitric acid.
(c) Metals like calcium and magnesium are never found in their free state in nature.
Answer : (a) Sodium chloride is an ionic compound but it conducts electricity only in molten and aqueous state because in molten and aqueous form the compound liberate to give ions. These ions move freely and hence conduct electricity.
(b) Reactivity of aluminium decreases if it is dipped in nitric acid because it is a strong oxidising reagent. The layer of aluminium oxide (Al2O3) prevents further reaction of aluminium due to which its reactivity decreases.
(c) Metals like calcium and magnesium are never found in their free states in nature they occur in the form of ores because these metals are present on the top of the reactivity series. They are highly reactive that they react with gases and surrounding elements, form compounds and thus are not found in free state.
Question: Write the electronic configuration of two elements X and Y whose atomic numbers are 20 and 17 respectively.
Write the molecular formula of the compound formed when element X reacts with element Y. Draw electrondot structure of the product and also state the nature of the bond formed between both the elements.
Answer : X = 20 : 2, 8, 8, 2
Y = 17 : 2, 8, 7
Question: What is a covalent bond ? What type of bond exists in
(a) CCl4, (b) CaCl2 ?
Answer : The chemical bond formed by the sharing of electrons between two atoms is known as a covalent bond.
(a) Covalent bonds in CCl4, (b) Ionic bonds in CaCl2.
Question: From amongst the metals sodium, calcium, aluminium, copper and magnesium, name the metal :
(a) Which reacts with water only on boiling,
(b) Another which does not react even with steam.
Answer : (a) Aluminium (b) Copper.
Question: (a) Draw the electron-dot structure of a hydrogen chloride molecule.
(b) (i) Which inert gas does the H atom in HCl resemble in electron arrangement ?
(ii) Which inert gas does the Cl atom in HCl resemble in electron arrangement ?
Question: What is an ionic bond ? What type of bond is present in oxygen molecule ?
Answer : The chemical bond formed by the transfer of electrons from one atom to another is known as an ionic bond. Covalent bond is present in an oxygen molecule.
Question: State reasons for the following observations :
(a) The shining surface of some metals becomes dull when exposed to air for a long time.
(b) Zinc fails to evolve hydrogen gas on reacting with dilute nitric acid.
(c) Metal sulphides occur mainly in rocks but metal halides occur mostly in sea and lake waters.
Answer : (a) It is because metal reacts with substances present in atmosphere to form surface compounds which make it dull.
(b) It is because dil. HNO3 is an oxidising agent therefore zinc gives NO and not H2 with dil. HNO3.
(c) It is because sea water contains sodium chloride due to which metal halides are formed, whereas sulphur is found below rocks. Therefore, metal – sulphides are formed in rocks.
Question: Why is sodium chloride soluble in water but not in kerosene and petrol ?
Answer : Water is a polar solvent and sodium chloride is an ionic compound. When sodium chloride is dissolved in water, it dissociates into ions. Therefore, it dissolves in it. On the other hand, kerosene and petrol are non-polar solvents. These cannot overcome the strong electrostatic force of attraction between the ions. And hence, NaCl does not dissolve into it.
Long Answers Type Questions
Question: (a) List in tabular form three chemical properties on the basis of which we can differentiate between a metal and a non-metal.
(b) Give reasons for the following:
(i) Most metals conduct electricity well.
(ii) The reaction of iron (III) oxide [Fe2O3] with heated aluminimum is used to join cracked machine parts.
(b) (i) Metals for example Na has an electronic configuration of 2, 8, 1 i.e., It has one free electron.
This electron moves through the metal and conducts electric current due to the presence of free electron.
(ii) Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(l) + Heat
It is thermite reaction.
This reaction is an exothermic reaction the reaction produces large amount of heat due to which iron metal is produced in molten form and use to join the tracks.
Question: (a) By the transfer of electrons, illustrate the formation of bond in magnesium chloride and identify the ions present in this compound.
(b) Ionic compounds are solids. Give reasons.
(c) With the help of a labelled diagram show the experimental set up of action of steam on a metal.
Ions present in this compound are Mg2+ and Cl–.
(b) Ionic compounds are solids and are somewhat hard because of the strong force of attraction between the positive and negative ions. These compounds are generally brittle and break into pieces when pressure is applied.
Question: Describe two methods for the concentration of ores.
Answer : Two methods used for separation of ores are :
(a) Froth Floatation method : This method is used generally to remove gangue from sulphide ores.
First of all, the ore is powdered and a suspension in water is formed. Then collectors and froth stabilisers are added. The collectors generally used are pine oils, fatty acids etc. The function of collectors is to increase the non-wettability of the metal part of the ore and allows it to form a froth.
Froth stabilizers (cresols, aniline etc.) sustain the froth. The oil wets the metal and the water wets the gangue. Paddles and air constantly stir up the suspension to create the froth. This frothy metal is skimmed off the top and dried, to recover the metal.
(b) This method is used in those cases where either ore or the impurities are of magnetic nature. In this method, the powdered impure ore in the form of thin layer is allowed to fall on a rubber belt which moves horizontally over two rollers, one of which has electromagnet attached to it. As the ore particles roll over the belt, the magnetic component in the ore gets attracted towards the magnet. It gets collected in a heap while the non–magnetic component forms a separate heap.
Question: (a) What are metals ? Name five metals.
(b) Name a metal which is so soft that it can be cut with a knife.
(c) Name the metal which is the best conductor of heat and electricity.
(d) What happens when a metal reacts with dilute hydrochloric acid ? Explain with the help of an example.
Answer : (a) Metals are the elements that conduct heat and electricity, and are malleable and ductile.
Example : Iron, aluminium, copper, gold and silver.
(d) When a metal reacts with dilute hydrochloric acid, it forms metal chloride and hydrogen gas.
Example : Magnesium reacts rapidly with dilute hydrochloric acid to form magnesium chloride and hydrogen.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
Question: Give the steps involved in the extraction of metals of low and medium reactivity from their respective sulphide ores.
Extraction of Mercury : Mercury is a metal of low reactivity. Cinnabar, i.e., mercury (II) sulphide is the ore of mercury. It is heated in air so that it is oxidised to produce mercury (II) oxide. After that, mercury oxide is reduced to obtain mercury. The following reactions are involved in this process :
2HgS + 3O2 → 2HgO + 2SO2.
Example : Extraction of Zinc : Zinc is in the middle of the reactivity series. It is found in the form of zinc blende which is zinc oxide. It is first heated in the presence of air to obtain zinc oxide. Zinc oxide is reduced to obtain pure zinc metal in the presence of carbon. This process can be shown by following equations.
2ZnS + 3O2 → 2ZnO + 2SO2
ZnO + C → Zn + CO
Question: State five uses of metals and non-metals.
Answer : Uses of metals :
(a) Copper and aluminium metals are used to make electrical wires.
(b) Zinc is used for galvanizing iron.
(c) Iron, copper and aluminium are used to make utensils.
(d) Lead metal is used in making car batteries.
(e) Aluminium is used to make aluminium foil for packaging materials.
Uses of non-metals :
(a) Hydrogen is used in the hydrogenation of vegetable oils.
(b) Carbon is used to make electrodes of electrolytic cells and dry cells.
(c) Nitrogen is used in the manufacture of ammonia, nitric acid and fertilizers.
(d) Sulphur is used for producing sulphuric acid.
(e) Liquid hydrogen is used as rocket fuel.
Question: (a) List in tabular form any three chemical properties on the basis of which metals and non-metals are differentiated.
(b) State two ways to prevent the rusting of iron.
(b) Rusting of iron can be prevented by :
(i) Painting, (ii) Oiling, (iii) Galvanization, (iv) Alloying.
We hope you liked the above provided Metals and Non-Metals Class 10 Science Exam Questions. If you have any further questions please put them in the comments section below so that our teachers can provide you an answer.