Which general symbol is used to represent lanthanoids?

Which of the following $f$-block elements exhibits the highest oxidation state?

Which of the following exhibits only $+3$ oxidation state?

State the $E^o$ values of lanthanoids and provide their reactions with the following: $(i)$ $H_2$,$(ii)$ Carbon,$(iii)$ Dilute acid,$(iv)$ Halogens,$(v)$ $O_2$,and $(vi)$ $H_2O$.

$(i) La(OH)_3$ is the least basic among lanthanide hydroxides. $(ii) Zr^{4+}$ and $Hf^{4+}$ have almost identical ionic radii. $(iii) Ce^{4+}$ can act as an oxidizing agent. Which of the above statements are correct?

Write the atomic number,name,symbol,and electronic configuration of Actinium and the Actinoids.