Question

How are elements classified in the periodic table?

Answer 1

Hint: Protons, neutrons, and electrons are the subatomic particles of an atom. To know the number of protons and neutrons present in an atom, the atomic number and atomic mass of the atom are required. The periodic table gives the idea about the hoe the elements are arranged. The atomic mass and the atomic number of atoms periodic table is used. In the periodic table, elements are arranged with increasing order of their atomic numbers. The position of an atom or element in the periodic table gives an idea about the atomic number of an element.

Complete step by step answer:
- In the modern periodic table, elements are arranged with increasing order of their atomic number that numbers of the protons present in elements.
- As we know that the periodic table consists of eighteen columns and seven rows. The vertical columns are called groups and the horizontal rows are called periods.

There are four blocks in the periodic table which are s-block, p-block, d-block, and f-block elements.
1. The elements in which valence shell electrons are present in s orbital are called s-block elements.
2. The elements in which valence shell electrons are present in p orbital are called p-block elements. Generally, s-block elements are metals and p-block elements are nonmetals and metalloids. The s and p block elements are called the main group elements.
3. The elements in which valence shell electrons are present in d orbital are called d-block elements. As this is present between the s-block metals and p-block non-metals they are called transition elements.
4. The elements in which valence shell electrons are present in f orbitals are called f-block elements. They are called inner transition elements.
 In this way, elements are classified into four blocks in the periodic table.

Note: In the periodic table s-block, p-block, d-block, and f-block are the four blocks in which all known elements are placed. The position of an element in the periodic table is important in determining the number of valence electrons.
- Atomic number represents the number of protons or electrons present in the element. The atomic number is represented by the letter Z.
- While the mass number is the total number of protons and neutrons present in the nucleus of an element. The mass number is represented by the letter A.
- The atomic number of an atom is always less than the atomic mass number of an atom.