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प्रश्न
What are actinoids? Give three examples.
उत्तर
- 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.
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संबंधित प्रश्न
Which of the following lanthanoid ions is diamagnetic?
Assertion: Ce4+ is used as an oxidizing agent in volumetric analysis.
Reason: Ce4+ has the tendency of attaining +3 oxidation state.
The actinoid elements which show the highest oxidation state of +7 are ____________.
What are inner transition elements?
Justify the position of lanthanides and actinides in the periodic table.
What is lanthanoid contraction and what are the effects of lanthanoid contraction?
Which of the following is not an actinoid?
The electronic configuration of gadolinium (Atomic number 64) is ______.
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 configuration, [Ne] 3s2 3p4 is for ______.
