Chemists who analyze samples for trace metals may buy standard solutions that contain 1000.0 mg/l concentrations of the metals.
if a chemist wishes to dilute a 1.000 × 10^3 mg/l stock solution to prepare 5.000 × 10^2 ml of a working standard that has a concentration of 7.000 mg/l, what volume of the 1.000 × 10^3 mg/l standard solution is needed?

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.