Chemical substances that alter perceptions and moods are called.

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.

Acetylene gas c2h2 undergoes combustion to produce carbon dioxide and water vapor how many grams of water are produced by the same amount of c2h2?