Hydrogen bonds, with a strength of about 5 kilocalories (21 kilojoules) per mole, are much weaker than normal covalent bonds, with bond energies of about 70 to 110 kilocalories per mole. (The amount of energy pe
aThe energy content in food can be measured directly using a bomb calorimeter or estimated using the following factors: 4 kilocalories per gram for carbohydrate and protein, 9 kilocalories per gram for fat, and 7 kilocalories per gram for alcohol. 能量内含在食物可以被测量直接地使用原子弹热量计...