Which of the following elements has a half-life in milliseconds?

With reference to aqua regia,choose the correct option$(s)$.
$(1)$ Reaction of gold with aqua regia produces $NO_2$ in the absence of air.
$(2)$ Aqua regia is prepared by mixing conc. $HCl$ and conc. $HNO_3$ in $3:1$ $(v/v)$ ratio.
$(3)$ Reaction of gold with aqua regia produces an anion having $Au$ in $+3$ oxidation state.
$(4)$ The yellow colour of aqua regia is due to the presence of $NOCl$ and $Cl_2$.

Which of the following interhalogen compounds has the lowest thermal stability?

When chlorine gas is passed over dry slaked lime,the product formed is ...........

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{I}_2O_5 + H_2O \longrightarrow HIO_3$

Which reaction has a positive value of $\Delta G^o$?