A chemistry teacher adds red food coloring to water and students observed the dye spreading out to fill the container. Is the teacher demonstrating a physical or chemical change?

Liv sheldon given the balanced equation for an organic reaction: c2h2 + 2cl2 → c2h2cl4 this reaction is best classified as *

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line