Explain the reason for classifying the periodic table into blocks

The long form of the periodic table divides the elements into four major blocks known as s, p, d, and f.

The period to which a given element belongs can easily be determined from its electron configuration. Based on electron configurations, the periodic table can be divided into blocks denoting which sublevel is in the process of being filled.

Hope it helps.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.