Iknow there are 4.5*10^-9 seconds in 4.5 nanoseconds, but when i enter it into my ti-30xiis, i get 4.5*10^-10. i enter it as 4.5 * (1/10^9) in my calculator what am i doing wrong?

You are not using properly the function exponential in your calculator

Explanation:

When a number is too big or too small we use scientific notation. This is a number between 1 a 10 multiplied by a power of 10.

When you are writing 4.5*10^-9 you are actually writing 0.0000000045 in scientific notation.

When you enter this in the calculator you have to use the function EXP after the first two numbers.

Steps:    1) Enter 4.5

             2) Enter EXP

             3) Enter minus (-)

             4) Enter 9

the correct answer is:

a. formation of precipitation