Question

What is the periodic trend in the variation of valency while going from left to right within a period?

Explain your answer with reference to period 2 and period 3.​

Answer 1

Answer:

" width="80%"> <br> The velency of an element is determined by the number of valuence elenctrons persent in the outermost shell of an atom of an element. <br> All the elements in a grop have the same numbr of valence elements. Therefore, elements in the same group should have the same valency. <br> For example, the elements of group , the valence electron, the valency of elements of group 1 is one. Similarly for group 2, (Be, Mg, Ca ) contain two valence electrons, the valency of elements of group 2 in two. <br> The elements of group 18 (Ne ,Ar ) contain 8 electrons (exception, Helium contain 2 electrons). Since the octect is complected their valency is zero.