Solutions of Metals and Non-metals (Page No - 172) - Chemistry Lakhmir Singh, Class 10 | Extra Documents, Videos & Tests for Class 10 PDF Download

Question 78:
The atomic number of an element X is 12.
(a) What must an atom of X do to attain the nearest inert gas electron configuration ?
(b) Which inert gas is nearest to X ?
Solution :
(a) An atom of X loses 2 electrons to attain the nearest gas electron configuration (2,8).
(b) Neon

Question 79:
The atomic number of an element Y is 16.
(a) What must an atom of Y do to achieve the nearest inert gas electron arrangement ?
(b) Which inert gas is nearest to Y ?
Solution :
(a) A n atom of Y a ccepts 2 electrons to achieve the nearest inert gas electron arrangement (2, 8, 8).
(b) Argon

Question 80:
You can buy solid air-freshners in shops. Do you think these substances are ionic or covalent ? Why ?
Solution :
Solid air-fresheners are covalent compounds because they are volatile compounds with low melting and boiling points.

Question 81:
Give the formulae of the chlorides of the elements X and Y having atomic numbers of 3 and 6 respectively. Will the properties of the two chlorides be similar or different ? Explain your answer.
Solution :
Formula of chloride of element X is XCl
Formula of chloride of element Y is YCl₄
The properties of two chlorides will be different because XCl is an i onic chloride whereas YCl₄ is a covalent chloride.