Evaluate each expression without using a calculator or changing the form of the expression. 

1. $\log(10)$ 

   Hint (a):

   Remember that $\log(x)$ is the same as $\log_{10}(x)$.

   Answer (a):

   $1$

2. $\log\left(\sqrt{10}\right)$ 

   Hint (b):

   $\log\sqrt{10}=\log10^{1/2}$

3. $\log(0)$ 

   Hint (c):

   $10^x=0$

4. $10^{(2/3)\log(27)}$ 

   Hint (d):

   $10^{(2/3)\log(27)}=10^{\log(27^{(2/3)})}$

   Answer (d):

   $9$