Question

Name the four blocks into which the elements of the periodic table have been classified. Why are they named so? List the periodic belonging to each block?

Answer 1

We have to know that the chemical elements are arranged in tabular columns and this tabular column is known as periodic table. And these elements are arranged in the periodic table in the increasing order of atomic number, electronic configuration. The starting element of the periodic table is hydrogen. And the periodic table has a total 18 groups and seven periods.

Complete answer:
We also need to know that in the periodic table, the blocks are classified into four types and that is, s- block, p- block, d- block and f- block. And this block is classified on the basis of the valence electron in which the shell is located.
In the case of s- block, the valence electrons are located in the s subshell. And s- block elements are hydrogen (H), lithium (Li), helium (He), sodium (Na), beryllium (Be), potassium (K), magnesium (Mg), rubidium (Rb), calcium (Ca), cesium (Cs), strontium (Sr), francium (Fr), barium (Ba), and radium (Ra).
In p- block, the valence electrons are entered in p and p- block elements are occupied in group $13$ to group $18$.
d- Block, the valence electrons are entered in d and these elements are occupied in group 3 to group $12$ .
And f- block, the valence electrons are entered in f. Total two series of f- block is presents which is 4f series and 5f series. And 4f series consist of compound cerium to lutetium. And 5f series consist of actinium to lawrencium.

Note:
We also remember that in the periodic table, the blocks are mainly classified into four, which is s- block, p- block, d- block and f- block. In the case of s- blocks, the valence electrons enter into the s subshell. Hence, for each block, the valence electrons enter into the respective subshells according to the block. And the elements arranged in the periodic table according to the increasing order of atomic number.