Question

define s p d f block elements

Answer 1

s-block elements: Those element in which last valence electron enters in s-orbital are called as s-block elements.

p-block elements: Those element in which last valence electron enters in p-orbital are called as p-block elements.

d-block elements: Those element in which last valence electron enters in d-orbital are called as d-block elements.

f-block elements: Those element in which last valence electron enters in f-orbital are called as f-block elements.

Answer 2

Explanation:

A block of the periodic table is a set of chemical elements having their differentiating electrons predominately in the same type of atomic orbital. A differentiating electron is the electron that differentiates an element from the previous one. For example, sodium ([Ne] 3s1), when compared to neon ([He] 2s2 2p6), has a difference of one s-electron. The term appears to have been first used by Charles Janet.[1] Each block is named after its characteristic orbital: s-block, p-block, d-block, and f-block.

The block names (s, p, d, and f) are derived from the spectroscopic notation for the value of an electron's azimuthal quantum number: sharp (0), principal (1), diffuse (2), or fundamental (3). Succeeding notations proceed in alphabetical order, as g, h, etc.