hydrogens average atomic mass = 1,01u
x = isotope about mass (1.0078u)
y = isotope about mass (2.0140u)
x + y = 100%
so:
x = 100% - y
[tex]hydrogens ~average~atomic~mass=\frac{(1.0078\cdot x)+(2.0140\cdot y)}{100}\\
1.01=\frac{(1.0078\cdot (100-y))+(2.0140y)}{100}||\cdot 100\\
101=100.78-1.0078y+2.0140\\
101-100.78=1.0062y\\
0,22=1.0062y||:1.0062\\
0.219\%=y\\\\
x=100\%-y\\
x=100\%-0.219\%\\
x=99.781\%\\\\
[/tex]
answer:
[tex]x=99.781\%\\
y=0.219\%[/tex]
