Question 17 braiding and cutting hair are both examples of physical changes. true false 2 points question 18 if you were to take several random samples from a mixture of salt and sand, the samples would: be identical no matter where in the mixture they were taken from be identical as long as the samples were taken at the same time be identical as long as the samples were the same size not be identical

Joseph has hypothesized that sound travels in waves. if he were following the scientific method, what should he do next? a. ask a question. b. test the hypothesis. c. study the results. d. tell other scientists about his hypothesis.

Problem page combustion of hydrocarbons such as pentane ( c5 h12 ) produces carbon dioxide, a "greenhouse gas." greenhouse gases in the earth's atmosphere can trap the sun's heat, raising the average temperature of the earth. for this reason there has been a great deal of international discussion about whether to regulate the production of carbon dioxide.(a) write a balanced chemical equation, including physical state symbols, for the combustion of liquid pentane into gaseous carbon dioxide and gaseous water. (b) suppose 0.350 kg of pentane are burned in air at a pressure of exactly 1 atm and a temperature of 20.0 degree c. calculate the volume of carbon dioxide gas that is produced.be sure your answer has the correct number of significant digits.

Amap that uses a range of colors and shading to represent the elevation, depth, or landscape of specific features on earth is a/an map.