Which of the following statements are true about elements? Choose the two correct answers. A.
Elements are the simplest form of matter.

B.
Elements combine together to form compounds.

C.
Elements are found in sunlight

D.
Elements are always positively charged.

E.
Elements are found in both living and nonliving things.

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.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Which rate indicates the number of children that would be born per woman if she were to live to the end of her child bearing years