Chapter 4 - Polynomials - 4.2 Negative Exponents and Scientific Notations - 4.2 Exercise Set - Page 245: 116

$0.5\times10^{-12}$

Using the laws of exponents and the concepts of scientific notation, the given expression, $ \dfrac{3.0\times10^{-2}}{6.0\times10^{10}} $, simplifies to \begin{array}{l} (3.0\div6.0)\times10^{-2-10} \\\\= 0.5\times10^{-12} .\end{array}