one sample had lead levels that reached 13.2x103 parts per billion by mass. Assume that there is a water reserve containing 1.00x106 kg of lead-contaminated water (solution). What is the mass of lead found in the reserve at these levels? What is the mass of lead if the reserve contained 9.00 ppb of lead, within the safe limits?
Answers (1)
First things first: We use Shift-6 for powers, so you have 13.2 x 10^3 parts/10^9 = 13.2 x 10^-6 which we would pronounce "13.2 parts per million."
physics.nist.gov/cuu/Units/prefixes.html
You just have to memorize this stuff, at least the ones you work with all the time. It's ok to bookmark the page so you can look up the others when you run across them.
There is a prefix every three powers of ten, except for 100, 10, 1/10, and 1/100. To go from one to another you use the LARD rule: LEFT ADD RIGHT DEDUCT. When moving the decimal to the LEFT you ADD to the power of ten. When going to the RIGHT you DEDUCT from the power of ten.
So now you take 13.2 x 10^-6 and multiply by 10^6 kg and you get 13.2 kilograms of lead. Do the other one the same way.