Matilda has a 100 g rock sample. she knows that the rock contains uranium-238 and that the half-life of uranium-238 is 4.5 x 109 years. if she cuts the rock sample in half, what happens to the half-life of the uranium

Nacidified solution was electrolyzed using copper electrodes. a constant current of 1.18 a caused the anode to lose 0.584 g after 1.52 ✕ 103 s. given that the charge of an electron is 1.6022 ✕ 10−19 c, calculate avogadro's number. assume that copper is oxidized to cu2+ ions.