00:02
Okay, so this question is about calculating the portion of isotopes.
00:09
So from the question we know in the nature, the boron has two isotopes.
00:18
One is bar 10 and another is bar 11.
00:26
And their mass, one is 10 .0129, another is 11.
00:35
0 .0093.
00:38
So first all we can do is we assume the portion of borough 10 is x in the nature.
00:57
Then the portion of the b11, right, boron 11 should be 1 minus x.
01:11
And now we can make the equation.
01:15
So the mass of the boron 10 times the portion of the boron 10 plus the mass of the boron 11 times the portion of the boron 11 should actually equal to the mass of the boron atom right in the nature reported in the periodic table so now what you can do is just plug in the numbers here so the mass of the boron atom right? is 10 .0129 x plus 11 .009 times 1 minus x and equals to 10 .811.
02:13
And now we can simply do the calculations here.
02:18
10 .029x plus 11 .029x plus 11 .0909...