## Chemistry: The Central Science (13th Edition)

$4.32\times10^5 seconds$
$(\frac{5 days}{1})\times(\frac{24 hours}{1 day})\times(\frac{3600 sec}{1 hour})=432000 seconds$ In order to do this unit conversion, first start with the given number, which in this case is 5 days. Then, put that unit on the bottom of the fraction next to it, for this will cancel out the unit. Doing this, the units days and hours cancel out, leaving the desired unit, seconds. Also, with the exception of the first fraction, the top and the bottom of the fraction must be equal, for they must cancel out. After all, it is legal to multiply a number by one, but it is not mathematically legal to multiiply a number, in this case 5 days, by a number that is not one in a unit conversion. For instance, 24 hours=1 day, so it is legal to multiply by $(\frac{24 hours}{1 day})$. This leads to the answer, 432000 seconds or $4.32\times10^5 seconds$.