Question

1. which of the following is the correct notation for an isotope with 3 protons and 5 neutrons?

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Explanation:

Step1: Determine the atomic number

The atomic number \(Z\) is equal to the number of protons. Given there are 3 protons, so \(Z = 3\). The element with atomic number \(Z=3\) is lithium (\(Li\)) (not \(U\) (atomic number \(92\)) or \(B\) (atomic number \(5\))).

Step2: Calculate the mass number

The mass number \(A\) is the sum of protons and neutrons. \(A=\text{number of protons}+\text{number of neutrons}=3 + 5=8\)

The general notation for an isotope is \(_{Z}^{A}\text{X}\), where \(Z\) is the atomic number and \(A\) is the mass number and \(X\) is the element symbol.

Answer:

\(_{3}^{8}\text{Li}\) (assuming the option with \(_{3}^{8}\text{Li}\) is present. If we consider the given options, likely there was a mis - label (maybe a typo in the problem's option display, but following the calculation: atomic number \(Z = 3\) (so element is \(Li\)), mass number \(A=8\))