A material originally contained 300 kg of uranium-235. The material now contains 281 kg of lead-207. Assuming that all the lead-207 came from the uranium-235,
how old is the material?

Select the correct answer. which statement applies only to the axial skeleton, not the appendicular skeleton? a. it contains a pivot joint. b. it has muscles attached that work in pairs. c. it contains red bone marrow. d. it possesses fossa for bone articulation. e. it protects the heart and lungs.