Helium makes very light than hydrogen
Please be a little more specific on what you want to ask. I can be of some help.
There is 10 kcal energy left in the 3rd trophic level.
Answer:
Due to different climatic condition.
Explanation:
Altitudinal zonation makes possible to grow many different types of crops because of different climatic condition of the region. Each and every plant has different climatic and environmental requirements due to which different plants can be grown on different places where environment is suitable. Some plants needs cool environment so they can be grown on high altitude while some needs warm temperature which can be grown on lower altitudes near the equator.
