A laboratory chemically separates out 50 mCi of pure Sr90 to use for research purposes. The Sr-90 is then stored in a vial for 48 hours prior to being used. What is the activity of Y-90 in the sample vial at that time?​

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.