a note on graphs with integer sombor index

For a graph $g$, the sombor index of $g$ is defined as $ so(g)=sum_{uvin e(g)} sqrt{deg(u)^2+deg(v)^2}$, where $deg(u)$ is referring to the degree of vertex $u$ in $g$. in this paper, we present a construction, namely $r_k$-construction which produce infinitely many families of graphs whose sombor indices are integers.