Help pls ! Lead-196 has a half-life of 37 minutes. It decays into thallium-196. Suppose a sample contains 20 atoms of lead-196 and 60 atoms of thallium-196. About
how old is the sample?

Atank has a shape of a cone with a radius at the top of 2 m and a height of 5 m. the tank also has a 1 m spout at the top of the tank. the tank is filled with water up to a height of 2 m. find the work needed to pump all the water out the top of the spout. (use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3.)