The atomic number of three elements are given below : {:("Element(Symbols)",A, B, C),("Atomic number",5,7,10):} Write the symbol of the elements which belongs to (a) group B, (b) groups 15, of the periodic table, state the period of the periodic table towhich these elements belong. Give reason for your answer.

The atomic number of three elements are given below : {:("Element(Sym

1.	The atomic number of three elements are given below : {:("Element(Symbols)",A, B, C),("Atomic number",5,7,10):} Write the symbol of the elements which belongs to (a) group B, (b) groups 15, of the periodic table, state the period of the periodic table towhich these elements belong. Give reason for your answer.
Answer» Solution :(a) A BELONGS to group B, because its electronic configuration is 2, 3 i.e, it has 3 valence electrons. (b)Bbelongsgroup15becauseitselectronicconfigurationis2, 5, i.e, it has 5 valence electrons.They belong to `2^(nd)` PERIOD as they both have TWO shells.