Question

Why transition metal less reactive then s block element

Answer 1

The reactivity of elements reduces as you move from left to right in a periodic table. S-block elements have one or two electrons in the outer most shell (valence shell) which makes them easier to move/share while reacting with other elements. On the other hand, in D-block the valence shell electron increases and its gets litter bit harder for them to react as compare to S-block elements.