Vinegar (acetic acid) and baking soda (sodium bicarbonate) are mixed to form sodium acetate, water, and carbon dioxide. Which of the following materials MUST be available in order to prove the law or conservation of mass?

Which statement is true about the model of the electromagnetic spectrum a: it change the frequencies of light. b: it compare wavelengths of light. c: the color of light waves can be changed using the model. d: the intensities of light waves can be decreased using the model.