How do humans perceive color? a. the optic nerve acts like a prism and separates white light into colors. b. photoreceptors on the retina detect different wavelengths of light. c. the pupil of the eye varies in size to absorb different wavelengths of color. d. the lens of the eye interprets the colors of the visible spectrum.

Which of the following changes will result in a stronger electromagnet? a. using fewer coils of wire b. using a higher voltage c. using a shorter nail d. using a longer wire

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

What electron configurations do atoms usually achieve by sharing electrons to form covalent bonds?