Question

current attempt in progress
the isotopic notation for an isotope that has an atomic number of 35 and a mass number of 81 would be:
○ ³⁵₈₁tl.
○ ³⁵₈₁br.
○ ⁸¹₃₅tl
○ ⁸¹₃₅br.

Explanation:

Step1: Recall isotopic notation

Isotopic notation is written as $_{Z}^{A}X$, where $A$ is the mass - number, $Z$ is the atomic number, and $X$ is the chemical symbol.

Step2: Identify the element

The atomic number $Z = 35$ corresponds to the element bromine, with the symbol $Br$.

Step3: Write the isotopic notation

Given $A = 81$ and $Z = 35$, the isotopic notation is $_{35}^{81}Br$.

Answer:

$_{35}^{81}Br$