The half-life for the process 238u→206pb is 4.5×109 yr. a mineral sample contains 61.0 mg of 238u and 15.5 mg of 206pb. part a what is the age of the mineral

Answer : The age of the mineral is,

Explanation :

First we have to calculate the rate constant, we use the formula :

Now we have to calculate the time.

Expression for rate law for first order kinetics is given by:

where,

k = rate constant

t = time passed by the sample  = ?

a = initial amount of the reactant  = 61.0 mg

a - x = amount left after decay process = 15.5 mg

Now put all the given values in above equation, we get

Therefore, the age of the mineral is,

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.