Lithium has 3 electrons. why do 2 electrons go in the first shell, and one in the second?
question 2 options:

a. the electrons go randomly into shells

b. the first shell only holds 2 electrons so the 3rd electron had to go in the second shell

c. all the electrons could go into the second shell.

d. the shells appear and disappear so the electrons go anywhere

Explain why in any given geographical region, women tend to have lighter skins( by 3-4% on average) than men?

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

Which of the following shows the correct order in which light information travels through the eye? (2 points) lens, pupil, retina, optic nerve pupil, lens, retina, optic nerve pupil, lens, optic nerve, retina lens, pupil, optic nerve, retina