Teaching BPSC 4.0 बिहार उच्च माध्यमिक शिक्षक भर्ती (PGT) Mock Test General Science Chemistry Periodic Table
Lanthanoids are:
1
14 elements in the sixth period( atomic number = 58 to 71) that are filling 4f sublevel.
2
14 elements in the sixth period ( atomic number = 90 to 103) that are filling 5f sublevel.
3
14 elements in the seventh period ( atomic number = 90 to 103) that are filling 5f sublevel.
4
More than one of the above
5
None of the above