Apulley system is because it decreases the

a. amount of effort needed to lift an object
b. amount of rope needed to lift an object
c. weight of the object
d. height that the object needs to be lifted

plz 20 points

How many electrons does silver have to give up in order to achieve a sido noble gas electron configuration

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.

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