Answer:
Nitrogen is the main component because it comprises 78% of total air while oxygen comprises 21%

Focus your attention to the units of the given data and the unit of the final measurement you're going to solve. Through dimensional analysis,you know that the working equation would be:
Food Value = CcalΔT/m
Food value = (6.15 kJ/°C)(1.29 °C)/0.611 g = 12.98 kJ/g
Convert kJ to cal (1 kJ = 239 cal)
Food value = 12.98*239 =<em> 3,103.28 cal/g</em>
By increasing Atomic number