Question

In f-block elements two outermost orbitals are​

Answer 1

There are two series in the f block corresponding to the filling up of 4f and 5f orbitals. The elements are 4f series of Ce to Lu and 5f series of Th to Lw.

Answer 2

In f-block elements two outermost orbitals are​ 4f and 5f orbitals.

Explanation:

• f block elements are called inner transition elements.
• They are also known as lanthanides and actinides
• The 28 elements from atomic number 58 to 71 and from atomic number 90 to 103  are f block elements.
• The elements in which the last electron enters into $(n-2)f$ orbitals are known as f block elements.
• They belong to group 3 in the periodic table.
• In lanthanoid, electrons enter 4f subshell whereas in actinides the last electrons enter into 5f subshell.