How do we capture and use solar energy

Modern atomic theory states that the atom is a diffuse cloud of surrounding a small, dense nucleus. a) electron b) neutron c) proton d) quark eliminate

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

How many dots must be added to the symbol to properly represent a standard nitrogen ion? a) 1 b) 3 c) 5 d) 8