please show me step by step solution to theaw two questions. im not sure where to start. thankyou for the help.

In chemical reactions, heat is converted into chemical energy (the potential energy stored in chemical bonds) or vice versa. Bond energy is the energy required to break one mole of the bond in the gas phase. Since it takes energy to break a bond, bond energies are always positive. Conversely, energy is released when bonds are formed. Thus, the enthalpy change for a reaction can be approximated from rH=(H breaking )+(H forming ) where H represents bond energies for the breaking (positive bond energy) or forming (negative bond energy) of a bond and Hr represents the overall enthalpy for the reaction. Use the table to answer questions about bond energies. where H represents bond energies for the breaking (positive bond energy) or forming (negative bond energy) of a bond and Hr represents the overall enthalpy for the reaction. Use the table to answer questions about bond energies. Calculate the bond energy for breaking all the bonds in a mole of methane, CH4. Express your answer to four significant figures and include the appropriate units. View Available Hint(s) Calculate the bond energy for breaking all the bonds in a mole of O2 molecules? Express your answer to three significant figures and include the appropriate units. View Available Hint(s)