- Which of the following is most basic Lu OH 3?
- Why are actinides called actinides?
- Why do actinides show higher oxidation states than lanthanides?
- Are lanthanides metals or nonmetals?
- Why are lanthanides Coloured?
- Which of the following is more basic hydroxide?
- How many lanthanides are there in the periodic table?
- Which element among the lanthanides has smallest atomic radius?
- What is the main cause of lanthanide contraction?
- Why are lanthanides all 3+?
- Are lanthanides radioactive?
- Why actinides are more basic than lanthanides?
- Why D and F block elements have poor shielding effect?
- Which lanthanide hydroxide is most basic?
- What are the consequences of lanthanide contraction?
Which of the following is most basic Lu OH 3?
La(OH)3 is most basic and Lu(OH)3 is least basic.
Due to lanthanide contraction.
As the size of lanthanide ions decreses from La3+ to Lu3+ , the covalent character of the hydroxides increases and hence the basic strength decreases..
Why are actinides called actinides?
They are called the lanthanides because they exhibit similar chemical properties to lanthanum, the first element in the group. Actinides are the 15 elements with atomic numbers from 89 to 103. They are named after the first element in the series, actinium.
Why do actinides show higher oxidation states than lanthanides?
Actinides exhibits larger oxidation states than lanthanides, because of very small energy gap between 5f, 6d and 7s sub shells. Thus, the outermost electrons get easily excited to the higher energy levels, giving variable oxidation states.
Are lanthanides metals or nonmetals?
The lanthanides are a group of 15 chemical elements, with atomic numbers 57 through 71. All of these elements have one valence electron in the 5d shell. The elements share properties in common with the first element in the group — lanthanum. The lanthanides are reactive, silver-colored metals.
Why are lanthanides Coloured?
The colour of lanthanide ions is due to the presence of partly filled f orbitals. As a result it is possible to absorb certain wavelength from the visible region of the spectrum. This results in transitions from one 4f orbital to another 4f orbital known as f-f transition.
Which of the following is more basic hydroxide?
Solution : Alkali metals form most basic hydroxide.
How many lanthanides are there in the periodic table?
14 elementsThe lanthanide series consists of the 14 elements, with atomic numbers 58 through 71, that follow lanthanum on the periodic table of elements. These 14, along with the actinides—atomic numbers 90 through 103—are set aside from the periodic table due to similarities in properties that define each group.
Which element among the lanthanides has smallest atomic radius?
lutetiumAnswer and Explanation: Of the lanthanide series atoms, lutetium (atomic number 71) has the smallest atomic radius of and the last element in the lanthanide series.
What is the main cause of lanthanide contraction?
The Lanthanide Contraction is caused by a poor shielding effect of the 4f electrons. Gd because as atomic number increases, the atomic radius decreases. … These electrons are do not shield good, causing a greater nuclear charge. This greater nuclear charge has a greater pull on the electrons.
Why are lanthanides all 3+?
The most common and stable oxidation state of Lanthanides is +3.It is attained by removing outermost 2 electrons of 6s electrons and 1 electron from 4f electrons. It is due to high energy difference in 4f and 6s, it is difficult to remove more electrons from 4f sub-shell.
Are lanthanides radioactive?
There are two rows under the periodic table: the lanthanide and actinide series. The lanthanide series can be found naturally on Earth. Only one element in the series is radioactive. … They are all radioactive and some are not found in nature.
Why actinides are more basic than lanthanides?
All actinides except thorium and amercium have high density. Ionization enthalpies: The actinides have lower ionization enthalpies as comapre to lanthanides because 5f is more effectively shielded from nuclear charge than 4f.
Why D and F block elements have poor shielding effect?
If the electron is in s orbital, it means it is nearest to nucleus and if in f shell, it means it is farthest from nucleus. Since, atomic shielding depends on electron density in a orbital and electron density is very less for d and f orbitals, hence it has poor shielding effect as compared to s and p orbitals.
Which lanthanide hydroxide is most basic?
La(OH)3 is most basic and Lu(OH)3 is least basic.Due to lanthanide contraction. As the size of lanthanide ions decreses from La3+to Lu3+, the covalent character of the hydroxides increases and hence the basic strength decreases.
What are the consequences of lanthanide contraction?
Basic Strength of Hydroxide: Due to the lanthanide contraction, size of M ions decreases and there is increase in covalent character in M–OH and hence basic character decreases.