Answer:
Approximately 
.
Explanation:
Lookup Avogadro's Number: 
(three significant figures.)
Lookup the relative atomic mass of 
, 
, and 
on a modern periodic table:
(For example, the relative atomic mass of is 
means that the mass of one mole of 
atoms would be approximately 
grams on average.)
The question counted the number of 
molecules without using any unit. Avogadro's Number 
helps convert the unit of that count to moles.
Each mole of molecules includes exactly 
of these 
molecules.
molecules would correspond to 
of such molecules.
(Keep more significant figures than required during intermediary steps.)
The formula mass of gives the mass of each mole of 
molecules. The value of the formula mass could be calculated using the relative atomic mass of each element:
.
Calculate the mass of approximately 
of :
.
(Rounded to three significant figures.)
Answer:
Subtract them.
Explanation:
''''"Since all number in scientific notation have base 10, we can always multiply them and divide them. To multiply two numbers in scientific notation, multiply their coefficients and add their exponents. To divide two numbers in scientific notation, divide their coefficients and subtract their exponents."""""
I was actually learned about this in school just found an source.
.
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