Materials : Metals and Non-Metals NCERT Solutions - Class 8 Science
1: What are the uses of metals and non-metals?
There are vast uses of metals and nonmetals in our day to day lives. All the electronics equipment which we use like TV, mobiles, fridges etc in daily life use metals in the body for different purposes. But one of the key purposes is to facilitate electricity transfer as metals are good conductors of electricity. Metals are also used in medicines as they are needed for conduction of nerve impulses, to carry oxygen by blood, to facilitate enzyme reactions, etc. Some metals are used to cure any micronutrient metal deficiency diseases in humans and animals. Other uses of metals are in Construction industries, jewellery making, machinery, automobiles, and many more. Similarly nonmetals find its uses in medical purposes. Nonmetals are often used as a powerful disinfectant, important ingredient in many chemical solutions but we also use it as an important element in combustion in batteries and in manufacturing. Nonmetals are also used to purify drinking water and swimming pools.
2: What are the differences between metals and nonmetals according to their physical properties?
On the basis of their physical properties metals and non-metals can be distinguished in the following ways. All metals are solid at room temperature except mercury, which is a liquid at room temperature but mon-metals can exist as solid, liquid or gas. All metals are lustrous whereas non-metals are non-lustrous. Metals have high densities except for lithium, sodium and potassium and nonmetals have a low density. Metals are malleable and ductile whereas nonmetals are not. Metals are good conductors of heat and electricity and have a high melting point but nonmetals are poor conductors of heat and electricity with low melting and boiling point.
3: Why NCERT solution of class 8 chapter 4 is the most reliable study material?
NCERT Solutions for Class 8 Chemistry Chapter 4 provides the simple and to the point answers to the exercise questions which are extremely helpful in understanding how to write answers in exams. The solutions are also very effective for exam preparations because it saves a lot of time by allowing fast revision. The solutions are designed by expert teachers as per the latest CBSE exam guidelines and syllabus. Hence, these are beneficial in scoring well in the Chemistry paper.
4: What are the topics covered in the chapter metals and non-metals?
The chapter discusses the physical and chemical properties of metals and nonmetals followed by the important reactions and uses of metals and non-metals. Under the physical and chemical properties of metals and nonmetals, following topics are discussed - the importance of metallurgy which is related to the physical and chemical behaviour of metallic and nonmetallic elements, the reactivity of metals and nonmetals, etc.. This chapter also deals with reaction of metals with acids and bases and also clears the concept as why non-metals generally do not react with acids but metals react with acids to produce ‘hydrogen gas’. Displacement reactions are also explained in the chapter.