Question

q3. you have a round pie plate filled with water. you carefully release a drop of red food coloring in the center of the plate. what happens to the red dye molecules right after the drop is placed?
dye molecules move in all directions and since most directions take them away from the drop, they spread out.
there are more total molecules concentrated within the drop compared to outside the drop, so they bounce off each other more in the drop and spread out.
dye molecules are repelled by the other dye molecules in the drop and the repulsion causes them to spread out.

Explanation:

The first option explains diffusion: molecules move randomly (Brownian motion), and since most paths from the drop's high - concentration area lead outward, they spread. The second option's "bounce off each other more" isn't the main reason for diffusion. The third option's "repelled by other dye molecules" is incorrect; diffusion is due to random motion, not repulsion between dye molecules.

Answer:

A. Dye molecules move in all directions and since most directions take them away from the drop, they spread out.