1.what is an atomic model ?
= A smallest particle of an element that can take part in chemical reaction without division is known as atomic model .
2. What is called atomic number and mass number?
=The total number of protons present in the nucleus of an atom is known as atomic number .
=The mass number of an atomic number is amu.
3. What is called an element?
=An element is the simplest pure form of a substance which cannot be split up into other simpler substance by any chemical method.