Atoms of seven elements A, B, C, D, E, F and G have a different number of electronic shells but have the same number of electrons in their outermost shells. The elements A and C combine with chlorine to form an acid and common salt respectively. The oxide of element A is liquid at room temperature and is a neutral substance while the oxides of the remaining six elements are basic in nature. Based on the above information, answer the following questions given ahead :
(i) What could the element A be ?
(ii) Will elements A to G belong to the same period or same group of the periodic table ?
(iii) Write the formula of the compound formed by the reaction of the element A with oxygen.
(iv) Show the formation of the compound by a combination of element C with chlorine with the help of electronic structure.
(v) What would be the ratio of number of combining atoms in a compound formed by the combination element A with carbon ?
(vi) Which one of the given elements is likely to have the smallest atomic radius ?

Explanation

Since all the seven elements have same number of electrons in their outer most shells, this means that they belong to the same group. From the available information, it becomes clear that the group is of alkali metals (group 1). Hydrogen (A) is also included. The elements present are,
`{:(H,Li,Na,K,Rb,Cs,Fr,),((A),(B),(C),(D),(E),(F),(G),):}`
Let us answer the questions asked
(i) The element 'X is hydrogen (H)
(ii) The elements 'X to 'G' belong to the same group and not same period
(iii) The formula of compound is `H_(2)O`
(iv) Compound between 'C' and chlorine (Cl) is sodium chloride (NaCl) formed by the transference of one electron.

(v) The compound formed between 'A' (H) and carbon is methane `(CH_(4)).` In this the two elements are present in the ratio of 1 : 4
(vi) The element A (hydrogen) has the smallest atomic radius since it is the first element of the group.