Which of the following element belongs to the second transition series of the periodic table?

Which isotope of plutonium is used in nuclear bombs?

Which of the following is used as a nuclear fuel?

How many series’ of transition elements are present in the periodic table?

Which of the following iswhy the atomic radii of the second and third transition series are almost same?

Which of the following metal is used as a thermometric liquid?

What is the formula of hematite?

In lanthanides, Ce changes from +4 to +3 oxidation state.