The two types of elements are metals and nonmetals. Except for mercury, all metals are solid at room temperature. Metals have a variety of distinguishing characteristics.
- They can be moulded.
- They are lustrous.
- They are good conductors of heat and electricity.
- As a result, they lose electrons and produce positively charged ions.
- They form basic oxides when they interact with oxygen.
In the chapter Metals and Non-metals, the features that must be considered when identifying elements as metals and non-metals are clearly explained.
Metallic lustre, hardness, malleability, ductility, and conductivity are examples of physical properties of metals and nonmetals discussed in this chapter.
In the section on chemical features of metals, the reactions of metals when burned in air, with water, with acids, and with the solution of other metals are thoroughly examined, with suitable examples and chemical formulae. In addition, the effect of steam on metals is explored. Metals and Non-metals includes a brief discussion of the anodization process.
A description of the reactivity series is also included in this chapter. Metals and non-metals' responses are explained using chemical reactions and formulae.
There's also a table with the electronic arrangement of some of the elements. The chapter concentrates on the properties of ionic compounds with the help of activities. The topic of metal occurrence is discussed in great detail. The stages involved in extracting metals from ores are shown in a flowchart format.
These NCERT Solutions for Class 10 Science Chapter 3 – Metals and Non-metals provide precise and simple NCERT problems.
These solutions include answers to all practice problems found in Chapter 3, Metals and Non-metals in the NCERT Class 10 Science textbook.
In addition, the answers to the questions posed in between chapters have been shared.
These answers will help students prepare for a range of competitive exams, such as JEE, NEET, and others.
Chapter 3 - Metals and Non-metals NCERT Solutions for Class 10 Science
Questions from the text:
1. Give an example of a metal that is used in construction.
At room temperature,
i. is a liquid.
Answer: Mercury
ii. is simple to cut with a knife.
Answer: Potassium
iii. is the best heat conductor.
Answer: Copper
iv. is a poor heat conductor.
Answer: Mercury
2. Define the terms malleable and ductile.
Ans: Malleability is the property of a metal that allows it to be pounded into thin sheets, and such metals are known to be malleable.
Ductile: The ability of a metal to be pounded into thin pipes/wire is referred to as ductility, and the metals are referred to as ductile.
3. Write equations of the following reactions of
i. iron with steam
Ans: 3Fe(s)+4H2O(g)→Fe3O4(s)+4H2( g)
ii. calcium and potassium with water
Ans: Ca(s)+2H2O(l)→Ca(OH)2(aq)+H2( g)
2 K(s)+2H2O(l)→2KOH(aq)+H2(g)+ heat
4. Why is sodium kept submerged in kerosene?
Ans: Sodium is a metal with high reactivity. As soon as it comes into contact with air, it reacts and catches fire. As a result, sodium is kept submerged in kerosene oil to avoid such mishaps.
5. Why do Ionic compounds have high melting points?
Answer : Ionic compounds have both positive and negative charges, called ionic compounds. As a result, there will be a strong attraction between them. Because breaking this force of attraction requires a lot of heat, ionic compounds have high melting temperatures.
6. When dilute hydrochloric acid is introduced to a reactive metal, which gas is produced? When iron reacts with dilute H2SO4, write the chemical reaction.
Ans: According to the reactivity series, iron is more reactive than hydrogen. As a result, iron substitutes hydrogen when it comes into touch with dilute H2SO4.
7. (I) Draw the sodium, oxygen, and magnesium electron-dot structures.
(ii) What are the ions that these compounds contain?
ANSWER:( I) The electron-dot structure for elements refers to representing elements with valence electrons as dots surrounding the elements.
(ii) Na+ and O2 ions are present in Na2O, while Mg2+ and O2 ions are present in MgO.
8. Define the terms below: Mineral, ore, and gangue are the three types of minerals.
Answer: (I) Mineral: Minerals are natural materials found on earth, including metals or their compounds.
(ii) Ore refers to the minerals from which metals can be mined easily and profitably.
(iii) Gangue: In an ore, gangue refers to undesired impurities such as sand, stony material, earth particles, limestone, mica, and so on.
9. Name two free-floating metals that can be found in nature.
Answer: Gold and platinum.
10. How is a metal separated from its oxide by a chemical process?
Answer: To separate a metal from its oxide, the reduction process is utilised.
Zinc oxide, for example, can be converted to metallic zinc by heating it with carbon.
ZnO(s) + C(s) = Zn(s) + COZnO(s) + COZnO(s) + COZnO(s) + COZnO( (g)
As reducing agents, highly reactive metals such as sodium, calcium, and aluminium are utilised. Low-reactivity metals are displaced from their oxides by these.
Fe2O3(s) + 2Al(s) = 2Fe(l) + Al2O3(s) + Heat, for example.
11. You've seen lemon or tamarind juice being used to clean tarnished copper objects. Why are these sour chemicals so efficient at cleaning the vessels?
Answer: Lemon or tamarind is used to clean tarnished copper vessels because the sour substance includes acids that dissolve the copper oxide or basic copper carbonate layer on the surface of the tarnished copper vessels. This restores their red-brown lustre. As a result, they're great for cleaning tarnished copper pots.
12. Provide reasons
(a) Jewellery is made from platinum, gold, and silver.
(b) Oil is used to store sodium, potassium, and lithium.
(c) Despite aluminium being a highly reactive metal, it is used to create cooking utensils.
(d) Carbonate and sulphide ores are frequently transformed into oxides during the extraction process.
Answer: (a) Because platinum, gold, and silver are highly reactive metals, they are unaffected by air, water, or most chemicals used to produce the jewellery. These metals have a high sheen, are malleable and ductile, and have good corrosion resistance.
(b) Sodium, potassium, and lithium release a lot of heat when combined with water. As a result, the reaction produces hydrogen, which causes a fire. They react with moisture (water droplets) in the atmosphere when exposed to water; hence these metals are stored under oil to avoid contact with water.
(c) Aluminium creates a nonreactive aluminium oxide surface on its surface. Other compounds can't react with aluminium because of the coating. As a result, aluminium is used to make cooking utensils.
(d) It is simple to convert metal oxide to free metal. Furthermore, because it is easier to acquire metals directly from their oxides rather than their carbonates or sulphides, the carbonate and sulphide ores must first be converted to oxides before the metals can be extracted.
13. You are given a hammer, a battery, a light, wires, and a switch.
(a) How could you use them to tell the difference between metal and non-metal samples?
(c) Evaluate the utility of these tests in separating metals from non-metals.
Answer: Metals are malleable and may readily be beaten into sheets with a hammer. Nonmetals, on the other hand, break down when beaten and cannot be made into sheets because they are non-malleable. Metals are good conductors of electricity; therefore, you get a bulb when you join metals with a battery, wire, and bulb. Nonmetals may also fail to light the bulb when connected to wire and battery if they are poor electrical conductors.
These experiments can be useful in demonstrating the malleability and conductivity of metals and non-metals.
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