# The relative atomic mass of 90Sr based on the 16O standard is 89.936. Based on the 12C standard, the relative atomic mass of 16O is 15,995. What is the relative atomic mass of 90Sr based on the 12C...

The relative atomic mass of 90Sr based on the 16O standard is 89.936. Based on the 12C standard, the relative atomic mass of 16O is 15,995. What is the relative atomic mass of 90Sr based on the 12C standard?

llltkl | College Teacher | (Level 3) Valedictorian

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Based on the 12-C standard, relative atomic mass of an element is defined as the mass of one atom of that element relative to 1/12th the mass of one atom of 12-C isotope.

Similarly, based on the 16O standard, relative atomic mass of an element is defined as the mass of one atom of that element relative to 1/16th the mass of one atom of 16-O isotope.

The relative atomic mass of 90-Sr based on the 16-O standard is 89.936 means,

(Mass of one atom of 90-Sr)/ (1/16*Mass of one atom of 16-O isotope)=89.936  --- (i)

Again,

The relative atomic mass of 16-O based on the 12-C standard is 15.995 means,

(Mass of one atom of 16-O)/ (1/12*Mass of one atom of 12-C isotope)=15.995  --- (ii)

(i)*(ii)

(Mass of one atom of 90-Sr)/ (1/16*1/12*Mass of one atom of 12-C isotope)=89.936*15.995

`rArr` (Mass of one atom of 90-Sr)/ (1/12*Mass of one atom of 12-C isotope)=(89.936*15.995)/16=89.9079

This is the relative atomic mass of 90-Sr based on the 12C standard.

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