Water will violently react to the alkali. All the alkali metals react directly with oxygen; lithium and sodium form monoxides, Li2O and Na2O, and the heavier alkali metals form superoxides, MO2.
<span>It may be difficult for ecologists to determine the size of a bird population if that population migrates to different locations throughout the year. During migration, some birds may split off from the group and not return, others may die, and still others may join. Therefore, the bird population will be in constant flux. It is hard to know, when the birds return to their prior location, if the population consists of the same group of birds (in addition to deaths and births) or whether it has grown or shrank through other means. However, to estimate the size, an ecologist can track a migratory flock through several years, counting each year to get a general sense of the population size. Additionally, given one measurement, an ecologist could consider the average lifespan and birth rates of the population to extrapolate the size of the population in subsequent years.</span>
<span>Having things other than chlorophyll (or bacteriochlorophyll or bacteriorhodopsin) absorbing the light will decrease productivity in any ecosystem whose biotic basis is photoautotrophs.</span>
D. Mitosis and Cytokinesis
