Question

Atoms of eight elements A. B. C. D, E, F. G and H have the same number of electronic shells but different number of electrons in their outermost shell. It was found that elements A and G combine to form an ionic compound. This compound is added in a small amount to almost all vegetable dishes during cooking. Oxides of elements A and B are basic in nature while those of E and F are acidic. The oxide of D is almost neural. Based on the above information answer the following questions:

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

(ii) What would be the nature of compound formed by a combination of elements B and F?

(iii) Which two of these elements could definitely be metals?

(iv) Which one of the eight elements is most likely to be found in gaseous state at room temperature?

(v) If the number of electrons in the outermost shell of elements C and G are 3 and 7 respectively, write the formula of the compound formed by the combination of C and G.​

Answer 1

Explanation:

1. all the elements belong to same period of periodic table

2. ionic compound

3. A and B

4. since most of the non metals are gaseous in nature therefore element F and G are gaseous

also if the arrangement of given elements are in the increasing order of their electronegativities

then element H can also be regarded as noble gas which is gaseous in nature

5. CG3

Answer 2

1. There are 8 elements and NaCl compound is also mentioned there. That means all elements lies in same period that is period 3.
2. As we know that oxides of A and B are basic in nature, that means A nd B are metals while E and F are non-metals. If B and F combines, ionic compound will be formed.
3. A and B
4. The extreme right position in periods are occupied by gaseous elements, so H is most likely to be in gaseous form.
5. C has 5 valency and G has valency 1, C will need 3 more electrons to complete its octet. And since C and G are metals and non-metals, they will form ionic compound by total sharing of electron. C will get 3 electrons from G but G has only 1 electron, so 3 G atoms will be required. Hence, the compound formed is $CG_3$