Two radioactive nuclides decay by successive fi rst-order processes: X 22.5 d f g Y 33.0 d f g Z (Th e times are half-lives in days.) Suppose that Y is an isotope that is required for medical applications. At what stage aft er X is fi rst formed will Y be most abundant

Silica, sio2, is formed on silicon as an electrically insulating layer for microelectronic devices. silica is formed when silicon is exposed to o2 gas at an elevated temperature. at 900˚c, it takes 90 minutes for the oxygen to diffuse from the surface to form a 0.06 micron (0.06 x 10-6 m) thick layer of sio2 on

1) these are barrel shaped microtubules in most animal cells, that organize the spindles during cell division

Aroller coaster car is traveling down a track at 22 m/s. the car has a mass of 2000 kg. what is the kinetic energy of the car? a) 22,000 j b) 968,000 j c) 484,000 j d) 44,000 j