One gram of lipid yields about 9kcal of energy. that is due to the high abundance of which chemical element?

The high energy of lipid molecule is due to the presence of hydrogen molecules. Due to the influence of lipid intermolecular hydrogen bonding, the energy required to break the hydrogen bond in lipid molecule is higher than protein and carbs and thus it yields more energy due to presence of hydrogen in it.

let that person have a turn to speak : )