The concentration of many toxic chemicals is measured in ppm (parts per million). One ppm means 1 gram of the chemical per million grams of substance. How many grams of lead are contained in 24.5 lb of blood (average for humans) if the Pb concentration is 0.62 ppm? Please use dimensional analysis to find your answer.

Asubstance is held in an open container. its particles move past one another at random speeds but do not leave the container. heat is removed from the system, and the particles slow down. when enough heat is removed, the particles no longer have enough speed to overcome the weak attractive forces between them. when this happens, the substance enters its solid state. the process described above is known as .