What type of bond is formed when two atoms share one or more pairs of valence electrons?

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

4. rat liver is able to metabolize glucose by both the glycolytic and the pentose phosphate pathway. which of the following are properties of both the glycolytic and pentose phosphate pathway? a. nad+ is involved b. co2 is liberated c. phosphate esters are intermediates d. glyceraldehyde 3-phosphate is an intermediate e. fructose 6-phosphate is an intermediate4. rat liver is able to metabolize glucose by both the glycolytic and the pentose phosphate pathway. which of the following are properties of both the glycolytic and pentose phosphate pathway? a. nad+ is involved b. co2 is liberated c. phosphate esters are intermediates d. glyceraldehyde 3-phosphate is an intermediate e. fructose 6-phosphate is an intermediate

Isolated volcanic peaks on the ocean floor are