The element X has an atomic mass of 12.80
amu. It is known to have two isotopes 12X and 13X. Which of the following is true about the relative abundancies of 12X and 13X?
a) both isotopes occur with the same frequency.
b)12X occurs more frequently than 13X
c)12X occurs less frequently than 13X
d) not enough information
Based on the information given, we can determine the relative abundances of the isotopes.
The atomic mass of element X is given as 12.80 amu. Since there are two known isotopes, 12X and 13X, we can assume that the atomic mass is a weighted average of the isotopes' masses and their respective abundances.
Let's assume the abundance of 12X is x, and the abundance of 13X is y.
The atomic mass can be expressed as:
(12X * x) + (13X * y) = 12.80 amu
Since the atomic mass is closer to the mass of 13X (13 amu) than 12X (12 amu), we can infer that 13X occurs more frequently than 12X. Therefore, the correct answer is:
c) 12X occurs less frequently than 13X
To determine the relative abundances of the isotopes 12X and 13X, we need to look at their atomic masses. The atomic mass of an element is the weighted average of the masses of all its isotopes, taking into account their abundances.
In this case, the atomic mass of X is given as 12.80 amu. Since there are two isotopes, 12X and 13X, we can set up the following equation using the atomic masses and relative abundances of the isotopes:
(12X * x) + (13X * y) = 12.80
Here, x represents the relative abundance of 12X, and y represents the relative abundance of 13X. We want to determine the relationship between x and y.
Since the question does not provide any information about the actual values of x and y, we cannot directly solve for them. Therefore, the correct answer is (d) not enough information.