Which statement about a chemical reaction is true?
it occurs only at low temperatures.
it occurs only at high temperatures.
it occurs whenever a physical change takes place
it occurs whenever a chemical change takes place.

For each of the following mixtures decide if filtering would be suitable to separate the substances. explain your answers. oil in water sugar in water sand in water chalk in water tea leaves in a cup of tea

What is the overall order of reaction for rate = k[no]2[o2]

About 70 percent of the earth's surface is water-covered, and about 96.5 percent of all earth's water is salt water. identify the watery feature on earth that is made of freshwater rather than salt water. a) bay b) glacier c) ocean d) sea it is not incomplete this is the true question