What are Nucleons?

We know that every atom contains protons,neutrons and electrons

Out of this

Protons and Nucleons are present in nucleus of atom

They are together called nucleons

Nucleons, Atomic Number and Mass Number-Teachoo-01.jpg

 

What is a Molecule?

A group of atoms chemically bonded together is Here are the valency of a few elements:

called Molecule.

 

What is atomic number?

It is the number of protons present in the nucleus of an atom

It is denoted by Z

 

Example 1

For Hydrogen, Z = 1

It means that in hydrogen atom, there is 1 proton present in the nucleus

Example 2

For Carbon, Z=6

It means that in carbon atom, there are 6 protons in the nucleus

 

What is a Molecule?

A group of atoms chemically bonded together is Here are the valency of a few elements:

called Molecule.

 

What is Mass Number?

It is the total number of protons and neutrons present in nucleus of atom

It is denoted by A.

Example 1

Carbon atom has 6 protons and 6 neutrons

So, Mass of Carbon is 6+6 = 12 u

Example 2

Aluminium atom has 13 protons and 14 neutrons

So Mass of Aluminium = 13+14 = 27 u

 

 

What is a Molecule?

A group of atoms chemically bonded together is Here are the valency of a few elements:

called Molecule.

  1. Class 9
  2. Chapter 3 Class 9 - Atoms And Molecules (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo