What is the activation energy of a reaction?

What is the equilibrium constant of aa+bb=cc+dd

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a