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 ?
Answers
Explanation:
(i) The elements A, B, C, D, E, F, G and H belong to the third period of the periodic table and to the following groups. A belongs to group 1 B belongs to group 2 C belongs to group 3 D belongs to group 14 E belongs to group 15 F belongs to group 16 G belongs to group 17 H belongs to group 18 (ii) The compounds formed by B and F would be ionic in nature. (iii) Elements A and B are definitely metals. (iv) Element H is most likely to found in gaseous state at room temperature. (v) The formula of the compound will be CG3.
(i) The listed chemicals belong to third period; it includes Na, Mg, Al, Si, P, S, Cl& Ar.
(ii) Compound formed by the combination of B (Mg) and F (S) will result in formation of salt called MgSO4
(iii) Compound A (Na) and B (Mg) are definitely metals as their oxides are basic in nature.
(iv) Element H (Ar), is likely to be found in gaseous state at room temperature as it is the 8th element of the group so it would have 8 electrons in its outermost shell which is the electronic configuration of an Nobel gas.
(v) They will form AlCl3 (Aluminium chloride).