How much argon is present in the earth's atmosphere? How is $\mathrm{Ar}$ obtained commercially and what is it used for?

Explain why $\mathrm{Ar}$ is used in the Kroll process to extract $\mathrm{Ti}$, for welding and in electric light bulbs. Draw the structures of ${\mathrm{XeF}}_2, {\mathrm{XeF}}_4$ and ${\mathrm{XeF}}_6$.

Explain why $\mathrm{Ar}$ is used in the Kroll process to extract $\mathrm{Ti}$, for welding and in electric light bulbs. How many of these compounds can be prepared from $\mathrm{Xe}$?

Among the following compounds, how may are prepared from $\mathrm{Xe}$ directly?

${\mathrm{XeF}}_2, {\mathrm{XeF}}_{4 } {\mathrm{XeF}}_6 \mathrm{and} {\mathrm{XeO}}_3$