Q23 of 44 Page 14

An element is sonorous and highly ductile. Under which category would you classify this element? What other characteristics do you expect the element to possess?

This element is a metal. Metals are sonorous and highly ductile. Some other characteristics of metals are as follows:
(i) Metallic lustrous and can be polished.
(ii) Metals are good conductors of heat and electricity.
(iii) Ductile
(iv) Malleable
(v) High tensile strength
(vi) High densities and melting point/boiling point
(vii) Hard (except sodium and potassium, which are soft metals)
(viii) Solid at room temperature (except mercury, which is liquid at room temperature)
Non-metals are neither malleable nor ductile and do not conduct electricity. Metalloids show some properties of metals and some other properties of non-metals.


More from this chapter

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21

You are given two samples of water labelled as ‘An’ and ‘B’. Sample ‘A’ boils at 100°C and sample ‘B’ boils at 102°C. Which sample of water will not freeze at 0°C? Comment.

 22

What are the favourable qualities given to gold when it is alloyed with copper or silver for the purpose of making ornaments?

 24

Give an example each of the mixture having the following characteristics. Suggest a suitable method to separate the components of these mixtures.

(a) A volatile and a non-volatile component.


(b) Two volatile components with appreciable difference in boiling points.


(c) Two immiscible liquids.


(d) One of the components changes directly from solid to gaseous state.


(e) Two or more coloured constituents soluble in some solvent.

 25

Fill in the blanks.

(a) A colloid is a ——— mixture and its components can be separated by the technique known as ———.


(b) Ice, water and water vapour look different and display different —— properties but they are ——— the same.


(c) A mixture of chloroform and water taken in a separating funnel is mixed and left undisturbed for some time. The upper layer in the separating funnel will be of——— and the lower layer will be that of —


(d) A mixture of two or more miscible liquids, for which the difference in the boiling points is less than 25 K can be separated by the process called———.


(e) When light is passed through water containing a few drops of milk, it shows a bluish tinge. This is due to the ——— of light by milk and the phenomenon is called ———. This indicates that milk is a ——— solution.