#### Answer

a) 7.461$\times10^{-11}$
b) 1.58$\times10^{-5}$
c) 6.32$\times10^{-7}$
d) 1.5$\times10^{-5}$

#### Work Step by Step

Scientific Notation is a simple way to represent very big or very small numbers, which are otherwise very tedious to write.
In this notation, we write the number in the form of a decimal and with an exponent to 10.
While writing a number in scientific notation, we need to remember that there is always only 1 digit before the decimal point.
When we move the decimal to the right, we include a negative sign in the exponent, and while moving to the left side, we include a positive sign in the exponent.
a) Here we are moving 11 digits to the right. So, the answer becomes 7.461$\times10^{-11}$.
b) Here we are moving 5 digits to the right. So, the answer becomes 1.58$\times10^{-5}$.
c) In this case, we are moving 7 digits to the right. Therefore, the answer is 6.32$\times10^{-7}$.
d) In this case, we are moving 5 digits to the right. Therefore, the answer is 1.5$\times10^{-5}$.