f-block elements (properties, classification)
Lanthanides and their general characteristics
Learn about f-block elements and what really these are.
study about lanthanides and actinides. you will also get to know about rare earth elements.
with cool transitions, slides and animation, i hope the students will learn more and more with ease and no difficulty.
3. List Slide
✔ Introduction
✔ Classification of F Block Elements
• Lanthanides
• Actinides
✔ Properties of f-Block Elements
✔ Lanthanides
✔ Common Characteristics of the
Lanthanides
4. f-block
Elements
Those elements in which the last electron that gets into
the f-orbital are called the f-block elements or Inner
transition elements.
5. There are mainly two series in the f-block that are equivalent to filling up of 4f
and 5f orbitals. The elements include 4f series of Ce to Lu and 5f series of Th
to Lr. 14 elements are there that fill up the ‘f’ orbital in each series.
6. Why are f-block elements called inner transition elements?
f-block elements are called inner transition elements because the last
electron enters the anti-penultimate shell, which is inner to the
penultimate shell in which the last electron of d-block elements enters.
Thus, d-block elements are called transition elements, and f-block
elements are called inner transition elements.
7. The final electron in an element's
atom moves to the valence shell,
which is the atom's outermost
shell. Penultimate shell refers to
the shell inner to the valence
shell, and pre-penultimate or anti-
penultimate shell refers to the
shell inner to a penultimate shell.
8. Properties of F-block Elements
They exhibit variable oxidation states.
They tend to form complex compounds.
The third last shell of the inner transition elements is filled
with electrons.
These elements make colorful ions.
The actinide series elements are radioactive.
Variable valencies are shown by the inner transition elements.
Elements beyond atomic number 92 till 103 are synthetic as
well as radioactive by nature.
9. Classification
The first series of elements are called
lanthanides and include elements with
atomic numbers beginning from 57 and
ending at 71. These elements are non-
radioactive (except for promethium, which
is radioactive).
The second series of elements are called
actinides and include elements with atomic
numbers beginning from 89 and ending at
103. These elements generally have a
radioactive nature.
Lanthanides Actinides
16. Common Characteristics of the Lanthanides
• Silvery-white metals that tarnish when exposed to air, forming their oxides.
• Relatively soft metals. Hardness increases somewhat with higher atomic
number.
• Moving from left to right across the period (increasing atomic number), the
radius of each lanthanide 3+ ion steadily decreases. This is referred to as
'lanthanide contraction'. Lanthanide contraction happens due to the poor
shielding of the 4f orbital. Due to this poor shielding, the outermost electron is
affected by the positive nuclear charge. Therefore, the atomic radius decreases
along with the series of the lanthanides.
• High melting points and boiling points.
• Very reactive.
17. • Burn easily in air.
• They are strong reducing agents.
• Their compounds are generally ionic.
• Most rare earth compounds are strongly paramagnetic.
• Many rare earth compounds fluoresce strongly under ultraviolet
light.
• The lanthanides react readily with most nonmetals and form binaries
on heating with most nonmetals.
• The coordination numbers of lanthanides are high (greater than 6;
usually 8 or 9 or as high as 12).
• The most stable oxidation state for lanthanide atoms is +3, but the +2
and +4 oxidation states are also common.
18. • REEs are a group of metals that includes the
lanthanides (lanthanum to lutetium), plus
scandium and yttrium.
• Rare-earth elements are not really very rare.
They are as common in the Earth’s crust as
tin, lead and zinc. They were named ‘rare
earths’ when they were discovered in the
19th century because they were found in
scarce minerals.
What are Rare Earth Elements?
19. Trick to remember Lanthanide series:
• Chemical Engineer (Ce)
• Poori (Pr)
• Neend (Nd) mein
• Prime Minister (Pm) ke
• Sang (Sm)
• Europe (Eu)
• Gye (Gd)
• Tabhi (Tb)
20. • Dikkat (Dy)
• Hui (Ho)
• Engineer (Er)
• Tum (Tm)
• Yahan Bhi (Yb)
• Lute (Lu)
