select the correct answer.\ncopper exists in nature as two isotopes. the atomic masses and relative…

select the correct answer.\ncopper exists in nature as two isotopes. the atomic masses and relative abundance of these isotopes is given in the table. what is the average atomic mass of copper?\n|isotope|relative abundance (%)|atomic mass (amu)|\n| ---- | ---- | ---- |\n|cu-63|69.17|62.93|\n|cu-65|30.83|64.94|\na. 62.93 amu\nb. 63.55 amu\nc. 63.935 amu\nd. 64.94 amu\ne. 127.87 amu

select the correct answer.\ncopper exists in nature as two isotopes. the atomic masses and relative abundance of these isotopes is given in the table. what is the average atomic mass of copper?\n|isotope|relative abundance (%)|atomic mass (amu)|\n| ---- | ---- | ---- |\n|cu-63|69.17|62.93|\n|cu-65|30.83|64.94|\na. 62.93 amu\nb. 63.55 amu\nc. 63.935 amu\nd. 64.94 amu\ne. 127.87 amu

Answer

Explanation:

Step1: Convert % to decimals

Cu-63: $\frac{69.17}{100}=0.6917$; Cu-65: $\frac{30.83}{100}=0.3083$

Step2: Calculate weighted mass for Cu-63

$0.6917 \times 62.93 = 43.53$

Step3: Calculate weighted mass for Cu-65

$0.3083 \times 64.94 = 20.02$

Step4: Sum weighted masses

$43.53 + 20.02 = 63.55$

Answer:

B. 63.55 amu