Suppose some radon gas enters your home. The half-life of 222Rn is 3.8235 days. What percentage of the 222Rn gas would still be present 6 days later (assuming it is only dissipated through nuclear decay)? Report your answer in percentage to one decimal place.

Both 1,2−dihydronaphthalene and 1,4−dihydronaphthalene may be selectively hydrogenated to 1,2,3,4−tetrahydronaphthalene. one of these isomers has a heat of hydrogenation of 101 kj/mol (24.1 kcal/mol), and the heat of hydrogenation of the other is 113 kj/mol (27.1 kcal/mol). match the heat of hydrogenation with the appropriate dihydronaphthalene.

The molecular formula for caffeine is cshion402. which of the following elements is not found in caffeine?

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as