calculate the average atomic mass of carbon of 98.9% of the atoms are C12 and 1.1% are c-13 atoms give your answer to the correct number of significant figures

Answer is: the average atomic mass of carbon is 12.011 amu.

m(¹²C) = 12.00 amu; the average atomic mass of carbon-12.  

m(¹³C) = 13.003354 amu; the average atomic mass of carbon-13.

ω(¹²C) = 98.90% ÷ 100% = 0.989; fractional abudance of carbon-12.

ω(¹³C) = 1.100% ÷ 100% = 0.011; fractional abudance of carbon-13.

m(C) = m(¹²C) · ω(¹²C) + m(¹³C) · ω(¹³C).  

m(C) = 12.0 amu · 0.989 + 13.003354 amu · 0.0110.  

m(C) = 12.011 amu; average atomic mass of carbon.

The unified atomic mass unit (amu) is a standard unit of atom  

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

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