10.800
12.015
18.5
1.10B=18.5/10mol
11B=81.5/11mol
100除以(18.5/10mol+81.5/11mol)=10.800
2.(12*65+13*7)除以66=12.015
3.设1mol Cl中 质量数37,质子为17的Cl有Xmol
37X+35(1-X)=35.5
x=25%
11.7除以(23+35.5)*25%*37=18.5
10.800
12.015
18.5
1.10B=18.5/10mol
11B=81.5/11mol
100除以(18.5/10mol+81.5/11mol)=10.800
2.(12*65+13*7)除以66=12.015
3.设1mol Cl中 质量数37,质子为17的Cl有Xmol
37X+35(1-X)=35.5
x=25%
11.7除以(23+35.5)*25%*37=18.5