Question

Need asap thank you

Answer 1

Answer:

c.boron-11

Explanation:

The atomic mass of boron is 10.81 u.

And 10.81 u is a lot closer to 11u than it is to 10u, so there must be more of boron-11.

To convince you fully, we can also do a simple calculation to find the exact proportion of boron-11 using the following formula:

(10u)(x)+(11u)(1−x)100%=10.81u

Where u is the unit for atomic mass and x is the proportion of boron-10 out of the total boron abundance which is 100%.

Solving for x we get:

11u−ux=10.81u

0.19u=ux

x=0.19

1−x=0.81

And thus the abundance of boron-11 is roughly 81%.