Answer :
Final answer:
To calculate the percentage abundance of the isotope X21, we use the average atomic mass and the known abundances of the other isotopes. We set up an equation using this data and solve it for the unknown, which is the percentage of X21.
Explanation:
In this problem, we're asked to find the percentage abundance of isotope X21 of element X, given the percentage abundance of isotope X20, along with the average atomic mass of element X. The abundance of one isotope can affect the average atomic mass of the element. The average atomic mass of an element is calculated by multiplying the atomic mass of each isotope by their respective abundance (then converting that abundance to a decimal) and then adding these values together. Using the formula for calculating average atomic mass:
Average atomic mass = (mass of isotope1 x abundance of isotope1) + (atomic mass of isotope2 x abundance of isotope2) + ....., we already know that the average atomic mass of X is 20.18, the mass numbers of the isotopes and the abundance of X20.
Since isotopes are atoms of the same element with different numbers of neutrons, isotopes X20, X21, and X22 of element X will have masses of 20, 21, and 22, respectively. We know that the abundance of X20 is 90% which leaves us with 10% to be distributed between X21 and X22. Calling the abundance of X21 as 'p' (in percentage) and X22 as '(10-p)', we can set up the equation: 20.18 (avg.atomic mass)= (20 x 0.9) + (21 x p/100) + [22 x (10-p)/100]
Solving the equation gives us the percentage abundance of X21, which would be the probability of that isotope occurring naturally out of 100 percent.
Learn more about Isotope Abundance here:
https://brainly.com/question/24873591
#SPJ11
