Which of the following statement is wrong?
Among the following elements: K, Mn, Cd, Cs, Fe, Cu, Pb, Os, Y
The number of transition element is 4.
All the lanthanides and actionides belong to III B or the 3rd group in the Periodic table
The inner transition elements belong to the f' block of the periodic table and are shown separately at the bottom of the periodic table.
The d-block elements have variable valency.
Statement (1) is wrong. The number of transition elements is five (Mn, Fe, Cu, Os, Y).