The diagrams at the right show the path of light as it passes from air into the three solids. What are the possibilities of the solids in A, B and C? Explain.

Atown is considering building a biodiesel power plant that would burn biomass to generate electricity. which of the following correctly lists an advantage and a disadvantage of this project?

What happens when the number of protons in an atom changes

Based on the diagram of the electric field lines around the two spherical charges, what are the signs of the left and right charge respectively?