f-Block Elements
Lanthanides and actinides in which the 4f or 5f subshell is being filled.
Practise Atomic Structure & Periodicity All Atomic Structure & Periodicity topics
Lanthanides and actinides in which the 4f or 5f subshell is being filled.
Practise Atomic Structure & Periodicity All Atomic Structure & Periodicity topics
The f-block consists of the lanthanides, in which the 4f subshell is being filled, and the actinides, in which the 5f subshell is being filled. Their chemistry is very similar within each series because the f electrons lie deep inside the atom and are shielded from bonding. Many actinides are radioactive, and several, including uranium and plutonium, are important in nuclear technology. The lanthanide contraction is a notable consequence of poor 4f shielding. These elements are usually displayed as a separate row below the main table.
Key ideas: Lanthanides (4f, Ce to Lu) and actinides (5f, Th to Lr) fill (n-2)f. Lanthanides are mostly +3 and chemically very similar, which makes separation hard (ion exchange is used). Actinides show more oxidation states (U +3 to +6) and are all radioactive. The Group 3 question: La or Lu below Y is debated.
Common mistakes and connections: Students think f-block elements are rare because of the name rare earths; Ce is as abundant as copper. Another is believing the f block is a separate group. The f electrons are inner and shielded poorly, causing lanthanide contraction. Actinides link to nuclear fuel (U, Pu) and nuclear chemistry.
Across the lanthanides the 4f subshell fills from 1 electron in Ce3+ to the full 14 in Lu3+, which is why the series has 14 elements. The interactive lesson shows this as a live animation or chart.
Neodymium, a lanthanide, is used in the strong neodymium-iron-boron permanent magnets found in electric motors and headphones.
Lanthanides and actinides in which the 4f or 5f subshell is being filled.
f-Block Elements is a beginner topic in Atomic Structure & Periodicity. It needs no earlier chemistry lessons and is a good starting point.
Study these earlier topics in Atomic Structure & Periodicity first: s-Block Elements, p-Block Elements, d-Block Elements.
The next topics in Atomic Structure & Periodicity are Metals Nonmetals and Metalloids and Atomic Radius.
Yes. The interactive lesson includes a self-check question on f-Block Elements, and the Atomic Structure & Periodicity quiz draws on every topic in this area.
f-Block Elements is topic 81 of 115 in Atomic Structure & Periodicity.