If a mole of $H_2$ molecules is heated to a high temperature,which of the following reactions takes place?

• A
  $H_{2(g)} + 436 \, kJ = H_{(g)} + H_{(g)}$
• B
  $H_{2(g)} + 820 \, kJ = 2H_{2(g)}$
• C
  $2H_{2(g)} + 436 \, J = 2H_2$
• D
  $H_2 + H_2 = H^{+} + H^{+}$