Question

16 an isotope of xenon has an atomic number of 54 and contains 77 neutrons. what is the xenon isotopes mass number? * (0.5 points) enter your answer

Explanation:

Step1: Recall mass - number formula

The mass number ($A$) of an atom is the sum of the number of protons ($Z$) and the number of neutrons ($N$), i.e., $A = Z+N$.

Step2: Identify values of $Z$ and $N$

The atomic number is equal to the number of protons. Given that the atomic number $Z = 54$ and the number of neutrons $N=77$.

Step3: Calculate the mass number

Substitute the values into the formula: $A=54 + 77=131$.

Answer:

131