Answer:
4.9cm or 4.90cm
Explanation:
Use column method and align the numbers. Make sure you add the decimal point before you write the answer, otherwise the value would be wrong.
Whichever one has the smallest amount of H+ Ions.
100%-64% to obtain the remaining% of the isotopes
= 36%
then,
atimic weight= (64×51) + (36×51)
=5100 amu