What determines an atom's reactivity? #1. how many protons the atom contains.
#2. How many energy levels the atom contains.
#3. whether the atom is a metal or a nonmetal
#4. how many valence electrons the atom contains.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

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