Osmium, Os$,$ with a density of $22\mathrm{.}57\frac{g}{c}{m}^3$ is the densest metal on the periodic table.

a$)$ What is the full electron configuration and noble gas notations of osmium?

b$)$ What are the noble gas configurations of $O{s}^{+}$and $O{s}^{3**}$

c$)$ The most abundant isotope of osmium is ${?}^{190}Os.$ What is the combined mass of neutrons in a $1\mathrm{.}00g$ sample of ${?}^{190}Os?$