Which lanthanoid from following has highest ionisation $\left(\mathrm{IE}_1\right)$ enthalpy?

For a reaction $\mathrm{A} \rightarrow$ Product, rate constant is $6.93 \times 10^{-3}$ hour ${ }^{-1}$. What is order of reaction?

Calculate the value of dissociation constant of weak acid, which dissociates to $0.01 \%$ in its 0.1 M solution?

What is the number of electrons in bonding molecular orbitals and antibonding molecular orbitals respectively in $\mathrm{F}_2$ molecule?