Answer:
Lead with an average atomic mass of 207.2.
Explanation:
To calculate the average atomic mass using isotopes we must multiply each of the masses by their percent abundances divided by 100. We must then add these values together to get the average atomic mass.
203.973u × 0.0140 = 2.86u
205.9745u × 0.2410 = 49.64u
206.9759u × 0.2210 = 45.74u
207.9766u × 0.5240 = 109.0u
109.0 + 45.74 + 49.64 + 2.86 = 207.2u
To identify the element we must check the periodic table for an element with our calculated average atomic mass.
Lead (Pb) has an average atomic mass of 207.2u.