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Question
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Atomic sizes
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Solution
- Generally, ions or atoms of the same charge in a series show a gradual decrease in radius with increasing atomic number, although this decrease is very small.
- In the same respective vertical column (group), the size of the atoms of the 4d series is larger than that of the corresponding elements of the 3d series. However, the size of the corresponding elements of the 5d series is almost the same as that of the 4d series.
- The reason for this nearly identical size between 4d and 5d series elements is Lanthanoid Contraction, which cancels out the expected increase in size due to the addition of a new shell.
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