Question

1. write the atomic symbol (symbol notation) for the two isotopes of uranium(u), whose atomic number is 92. one isotope has 142 neutrons, and the other isotope has 146 neutrons.

Explanation:

Step1: Calculate the mass number for the first isotope

The mass number \(A\) is the sum of the atomic number \(Z\) and the number of neutrons \(N\). Given \(Z = 92\) and \(N=142\), then \(A=Z + N=92+142 = 234\). The atomic symbol is written as \(_{Z}^{A}\text{Element Symbol}\), so for this isotope it is \(_{92}^{234}\text{U}\).

Step2: Calculate the mass number for the second isotope

Using the same formula \(A = Z+N\), with \(Z = 92\) and \(N = 146\), we get \(A=92 + 146=238\). The atomic symbol is \(_{92}^{238}\text{U}\).

Answer:

The atomic symbols are \(_{92}^{234}\text{U}\) and \(_{92}^{238}\text{U}\)