Which of the following can indicate that a chemical change has occurred? (Select all that apply)

A. burning

B. temperature change

C. light is emitted

D. color change

E. a change in smell or taste

When (2S, 3S)-2,3-dibromohexane undergoes reaction with sodium iodide in acetone, the product is A. cis-2-hexene. B. trans-3-hexene. C.cis-3-hexene. D. 1-hexene.E. trans-2-hexene.

Which alkene is the major product when 2-bromo-2-methylpentane is heated with sodium ethoxide in ethanol? A. (Z)-2-methyl-3-pentene B. 2-methyl-4-pentene C. 2-methyl-2-pentene D. 2-methyl-1-pentene E. (E)-2-methyl-3-pentene