Which of the following reacts with cold water vigorously

Which of the following reacts with cold water vigorously?

  1. carbon
  2. sodium
  3. magnesium
  4. sulphur

Answer

The vigour (or intensity) of reaction of a metal with water depends on its chemical reactivity.

Sodium is a very reactive metal, so it reacts violently even with cold water.

The correct option is B.