Helium has an atomic number of 2 so it's outer energy level is full. hellium is considered
a)nuetral
b)inert
c)an anion
d)a cation

Which of the following would be least likely to support the modern concept of biological evolution? ( 2 points) a)different species of organisms with similar bone patterns b)different species of organisms with similar reproductive rates species in c)different domains with similar metabolic pathways species in d)different kingdoms with similar cellular structures.

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?