Sodium and potassium react with water much more vigorously than lithium because:

• A

  Sodium and potassium have high values of hydration energy as compared to that of lithium.
• B

  Sodium and potassium have higher melting point than that of lithium.
• Correct answer
  C

  Sodium and potassium have lower melting point than that of lithium.
• D

  Sodium and potassium have lower hydration energy than that of lithium.

Solution

When sodium and potassium react with water, the heat evolved causes them to melt, giving a larger area of contact with water, lithium on the other hand, does not melt under these conditions and thus reacts more slowly.

Hence, the correct answer is option: 'C'.