Which processes represent one chemical change

and one physical change?

(1) freezing and melting

(2) freezing and vaporization

(3) decomposition and melting

(4) decomposition and combustion

Why are food preservatives added to food? O A. to increase the rate of reaction O B. to decrease the rate of reaction OC. to decrease potential energy of the reactants OD. to increase the temperature of the reaction

What kind of reactions are redox reactions a. reactions involving substituting different isotopes b. reactions involving losing and gaining electrons c. reactions involving protons transferring between atoms d.

A solution containing an equal number of hydrogen ions and hydroxide ions isA. basicB. alkalineC. acidicD. neutral.

The production capacity for acrylonitrile (C3H3N) in the United States exceeds 2 million pounds per year.

What is light? A wave of vibrating electric and magnetic energy A wave that travels by compressions A wave that travels by rarefactions A state of matter

According to the graph, which activity has used the largest amount of water over the past twenty years?

Tiffany leaves balloons filled with helium gas inside her car in on a sunny day when she returns to her car some some of the balloons are much larger and a few have popped explain what happened

If the pH indicator bromothymol blue was added to the nitric acid solution, it's colour would be?

Which statement describes a chemical reaction? Atoms in the products are rearranged to form new substances. Atoms in the reactants are rearranged to form new substances. Atoms in the products change into new atoms to form new substances.

The gases CO₂ (g) and NH₃ (g) can be liquefied at 20°C by compressing them to sufficiently high pressures. A student claims that NH₃ (g) can be liquefied at a lower pressure than CO₂ (g) can be liquefied.