Question

Which of the following is true 1) All transition elements are metallic, but more electropositive than alkaline earths 2) All actinides are synthetic and radioactive 3) All s-block and all p-block elements are representative elements 4) All d-block and all f-block elements are metals

Answer 1

Answer:

A block of the periodic table is a set of elements unified by the orbitals their valence electrons or vacancies lie in.[1] The term appears to have been first used by Charles Janet.[2] 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.