Suppose that the atomic mass unit (amu) had been defined as one-twentieth of the average mass of an atom of fluorine instead of one-twelfth of the mass of an atom of carbon-12. What would the average atomic mass of magnesium be on this new scale?
2.56×101
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What would the value of Avogadro's number be on this new scale?

Question

Suppose that the atomic mass unit (amu) had been defined as one-twentieth of the average mass of an atom of fluorine instead of one-twelfth of the mass of an atom of carbon-12. What would the average atomic mass of magnesium be on this new scale? 
2.56×101
You are correct.
Your receipt no. is 153-7616 Help: Receipt	Previous Tries
What would the value of Avogadro's number be on this new scale?

abmon98 · Answer

Given new atomic mass = 1/20 of the average mass of an atom of fluorine 
Atomic mass of fluorine=20 nmu 
Now atomic mass of Mg = [amu (Mg)/ amu(F)] x nmu(F) 
(24/19)*20=25.26
19/20*6.02*10^23