Question

Why is the reaction of lithium with water less vigorous?

Answer 1

because,lithium have highest melting point ,in it's group ,when dropped in water,most of the heat liberated in reaction with water is utilized to melt the lithium metal,and reaction occurs..........

Answer 2

as we move down group 1 the atomic size increases and reactivity with water increases therefore Li reactsless vigorously with H2O