In modern periodic table, if two elements have the same number of valence electrons, then they belong to the same :
Question 33 Three elements A, B and C have 3, 4 and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the Modern Periodic Table. Also, give their valencies.
If an element is in group 15 of a modern periodic table then the number of valence electrons it has is