Which characteristic is common to all three groups of mammals? they require little or no parental care. they develop partially or fully inside the mother’s body. they have long gestation periods. they are always endotherms.

To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert "blanketing" gases. a chemical engineer places a mixture of noble gases consisting of 4.37 g of he, 13.36 g of ne, and 36.65 g of kr in a piston-cylinder assembly at stp. calculate the partial pressure in torr of kr.