A certain negative ion "X"^(2-) has 18 neutrons in its nucleus and 18 electrons in its extra-nuclear structure. What is the mass number of the most abundant isotope of "X" ?
1 Answer
Explanation:
You know that this negative ion has a total of
As you know, the net charge of an ion is given by the difference that exists between the number of protons located inside its nucleus and the number of electrons surrounding its nucleus.
"net charge = no. of protons " - " no. of electrons"
You can use the fact that the ion has a
"no. of protons" = (2-) + 18 = 18 - 2 = 16
So, you know that element
The mass number of an atom,
A = Z + "no. of neutrons"
This means that this particular isotope of
A = 16 + 18 = 34
Now, in order to check whether or not this particular isotope is also the most abundant, you must grab a Periodic Table and look for the element that has
You will find that element
https://sciencenotes.org/periodic-table-element-cells/
Notice that sulfur has an atomic mass of
In this case, you have
32.066 ~~ 32
This means that the isotope that you're dealing with here, i.e. sulfur-34, is not the most abundant isotope of sulfur. The most abundant isotope of sulfur is, in fact, sulfur-32,