Q. 284.2( 5 Votes )
The positions of three elements A, B and C in the periodic table are shown below:
(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A ?
(a) Metallic character of elements decrease as we move horizontally left to right in the periodic table. The element A belongs to group 17 which is on the right side of the periodic table. Hence, element A does not show metallic character. It is a non-metal.
(b) The chemical reactivity decreases on going down in a group. Thus, element C is less reactive than element A.
(c) The atomic size decrease on going from left to right in a period. Hence, the atom of C will be smaller in size than an atom of B.
(d) Element A belongs to group 17 which has 7 valence electrons. It needs one electron to get noble gas configuration. So, it will accept 1 electron and form a negatively charged ion, A-. The negatively vahrged ion is called an anion. Thus, element A will form an anion.
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Account for the following:
a. Cations are smaller in size than the corresponding atom.
b. The noble gases were discovered very late.Xam idea - Science
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