The half-life of radium-226 is 1590 years. if a sample contains 300 mg, how many mg will remain after 4000 years?

What are the variables in gay-lussac’s law? pressure and volume pressure, temperature, and volume pressure and temperature volume, temperature, and moles of gas

Calculate the mass of silver needed to react with chlorine to produce 126g if silver chloride?

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.