smc

After rewriting the radicals as fractional exponents, the sequence is $2^{1/2},2^{1/3},2^{1/6}$. The common ratio of the geometric sequence is $\frac{2^{1/3}}{2^{1/2}}=2^{-1/6}$. Multiplying that by the third term results in $2^0$. It simplifies to $1$, so the answer is $\boxed{1}$.