A rock has a mass of 40 grams. When analyzed the rock is found to contain 10 grams of radioactive material 30 grams of a stable product. How many half-lives old is the rock?

Which type of stress results when two plates push against one another? a. compression b. tension c. force d. shear

Ahypothrticalax type of ceramic material is known to have a density of 2.10 g/cm3 and a unit cell of cubic symmetry with a cell edge length of 0.57 nm. the atomic weights of the a and x elements are 28.5and 30.0 g/mol, respectively. on the basis of this information, which of the following crystal structures is (are) possible for this material: sodium chloride, cesium chloride, or zinc blende

Gymnast always perform on padded mats. how does the mats protect the gymnast