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प्रश्न
What are actinoids? Give three examples.
What are actinoids?
What are actinoids? Give two examples of actinoids.
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उत्तर १
- The fourteen elements following actinium, i.e., from thorium (Th) to lawrencium (Lr) are called actinoids.
- All the actinoids are radioactive and most of them have short half-lives.
- The heavier members being extremely unstable and not of natural occurrence. They are produced synthetically by the artificial transformation of naturally occurring elements by nuclear reactions.
- Example: Thorium, Uranium, Plutonium, Californium.
उत्तर २
- The second series of rare earths, or the second inner transition series, is another name for the actinoid series.
- This series, which includes fourteen elements ranging from thorium (Th, At. No. = 90) to lawrencium (Lr, At. No. = 103), involves the filling of 5f-orbitals in the atoms.
- These elements have physical and chemical characteristics that are very similar to those of actinium (Ac, At. No. = 89), which comes after it in the periodic table. They are called actinoids for this reason.
Notes
Students should refer to the answer according to their questions.
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संबंधित प्रश्न
Write the general outer electronic configuration of f- block elements.
Which of the following oxidation states is most common among the lanthanoids?
The most common oxidation state of actinoids is ____________.
The actinoid elements which show the highest oxidation state of +7 are ____________.
What is lanthanoid contraction and what are the effects of lanthanoid contraction?
Actinoid contraction is greater from element to element than the lanthanoid contraction, why?
Why do zirconium and Hafnium exhibit similar properties?
In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.
The element with atomic number 57 belongs to ______.
In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.
The elements with atomic numbers 35, 53 and 85 are all ______.
Electronic configurations of four elements A, B, C and D are given below:
(A) 1s22s22p6
(B) 1s22s22p4
(C) 1s22s22p63s1
(D) 1s22s22p5
Which of the following is the correct order of increasing tendency to gain electron:
