Based on the food chain below, if a bald eagle acquires 50 kg of energy, how much energy did the herbivorous duck get from the aquatic vegetation?
aquatic vegetation --> herbivorous duck --> bivalves --> sea ducks --> bald eagle
i know its 50,000 kg but how is the division worked down?

50,000 x 0.10 = 5,000J

10 percent rule

Food chain refers to a process cycle from producer to consumer to decomposer.
Plants – herbivores – omnivores – carnivores Start -> Plants -> herbivore insect -> spiders -> small bird -> Snake -> hawk -> fox -> lion -> when died the body will be eaten by hyena-> when hyena died -> body get decompose and be eaten  by worms and the rest will be plant’s fertilizer.

The process of the food chain will then again takes place over and over again.