Explain the 4 blocks of the periodic table. how many, what are they, and what is strange about block "d"?

Answer and explanation;

An element block is a set of elements located in adjacent element groups.

There are four blocks; s, p, d, f; which originated from descriptions of spectroscopic lines of atomic orbitals: sharp, principal, diffuse and fundamental.

s-block; the first two groups of the periodic table, the s-block metals:

P-block elements include the last six element groups of the periodic table, excluding helium. The p-block elements include all of the nonmetals except for hydrogen and helium, the semi-metals, and the post-transition metals.

D-block elements are transition metals of element groups 3-12. D-Block elements:

f-block; Inner transition elements, usually the lanthanide and actinide series, including lanthanum and actinium. These elements are metals which have:

Uniqueness of group D elements; Normally across the period atomic radii should decrease. But d-block elements do not follow this trend. It increases From V to Cr and them remains constant and decreases and remains constant again.

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