Fluorine has an atomic number of 9. the n = 1 energy level has two electrons, and the n = 2 energy level has seven electrons. flourine's valence is

+2
-2
+1
-1

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.

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