Atoms of eight elements A,B, C, D, E, F, G and H have the same number of electronic shells but are different in their outermost shells. It was found that elements A and G combine to form an ionic compound which can also be extracted from sea water.

Oxides of the elements A and B are basic in nature while those of E and F are acidic. The oxide of elements D is almost neutral.

Answer the following questions based on the information given here in :

(i) To which group or period of the periodic table do the listed elements belong ?

(ii) Which one of the eight elements is likely to be a noble gas ?

(iii) Which one of the eight elements would have the largest atomic radius ?

(iv) Which two elements amongst these are likely to be the non-metals ?

(v) Which one of these eight elements is likely to be a semi-metal or metalloid ?

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1 Answers

(i) A and B belong to group 1 and 2 because they form basic oxides. C belongs to group 13 as it has 3 valence electrons. D belongs to group 14 as it forms an almost natural oxide. E and F belong to group 15 and 16 as they form acidic oxides, G belongs to group 17 as it has 7 valence electrons, and H to group 18. They belong to 3rd period of the periodic table.

(ii) H belongs to noble gas

(iii) A has a largest atomic radius

(iv) E and F are likely to be non-metals

(v) D is likely to be metalloid or semi-metal.

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