Is vinegar a compound or a mixture?

Complete the following reactions using word and balanced equations including states. dilute phosphoric acid is added with a calcium hydroxide solution.

List four observations that indicate that a chemical reaction may be taking place

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