Question

fill in the missing words the element has several isotopes. one of the isotopes has the mass number of 54 amu, and the number of neutrons in the isotope is 28. this element is blank.

Explanation:

Step1: Recall the formula for mass number

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

Step2: Calculate the number of protons

We know that $A = 54$ and $N = 28$. Rearranging the formula to find $Z$, we get $Z = A - N$. Substituting the given values, $Z = 54 - 28 = 26$.

Step3: Identify the element

The number of protons (atomic number, $Z$) determines the element. An element with atomic number 26 is iron (Fe).

Answer:

Iron (or Fe)