Answer:
Boron
Explanation:
Step 1: Given data
Step 2: Calculate the average atomic mass (m) of the element
We will use the following expression.
m = m₁ × A₁ + m₂ × A₂
m = 10.0129 u × 0.1978 + 11.00931 u × 0.8022
m = 10.81 u
The element with an m = 10.81 u is Boron.