The probability density for finding a molecule at distance r from the origin at time t in the spherical coordinates is denoted by p(r,t) p(r,t)=8(Dt)3/21er2/4Dt show that: (a) pdV=1 (b) r2pdV=6Dt hint: you might find WolframAlpha useful for some integrals. https://www.wolframalpha.com/calculators/integral calculator/