Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but 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 ?

Atoms of eight elements A, B, C, D, E, F, G and H have the same number

1.	Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but 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 ?
Answer» Solution :(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 almost netural oxide. E and F belong to group 15 and16 as they form acidic oxides, G belongs to group 17as it has 7 valence electrons, and H to group 18. They belong to `3^(rd)` period of the PERIODIC table. (ii) H belongs to noble gas (iii) A has largest ATOMIC radius (IV) E and F are likely to be non-metals (v) D is likely to be metalloid or semi-metal.