Waiting for answer This question has not been answered yet. You can hire a professional tutor to get the answer.
The order of magnitude of the mass of Earth's atmosphere is ##10^18## kilograms. The order of magnitude of the mass of Earth's oceans is ##10^3## times greater. What is the order of magnitude of the mass of Earth's oceans?
##10^21##
In general ##color(white)("XXX")b^pxxb^q =b^(p+q)##
Therefore ##color(white)("XXX")10^18 xx 10^3 = 10^(18+3) = 10^21##