How many statements are correct?
Actinoids have only one stable oxidation state
Its very easy to study the chemistry of actinoids owing to there radioactive nature
Samarium has the lowest melting point among lanthanoids
Gadolinium has 7 electrons in the 4f subshell and 2 electrons in 5d subshell
Size of Zirconium(Zr) is very slightly less than that of Hafnium(Hf) owing to lanthanoid contraction
Cerium(IV) reacts explosively with water
Europium can show +2 oxidation state