Oxygen has an atomic number of 8. the n = 1 energy level has two electrons, and the n = 2 energy level has six electrons. oxygen's valence is

What is the phylum of soft bodied animals with a true bosy cavity and a three part body consisting of a foot visceral mass and a mantle

Hummingbirds drink nectar from flowers, while robins eat plant seeds. what does this reduce?

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of