28. Compare all the proposed models of an atom given in the chapter (structure of the
atom)
OR.
a) Indentify the most stable atom from the following. Also give a reason for your
answer.
1. Na 2. Cl 3. Al 4. Ar
b) Differentiate between atomic-mass and mass number.
c) What is the valency of:
i) Aluminium in aluminium sulphate.
ii) Sodium in sodium sulphate.
Answers
Answer:
Hlo
Here is your answer
Thompson Model Rutherford Model Bohr Model
In this model, an atom consists of a positively charged sphere and the electrons embedded in it. The number of electrons is equal to the number of protons so the atom is electrically neutral. In this model, there is a positively charged centre in an atom called the nucleus. Nearly all the mass of an atom resides in the nucleus. The electrons revolve around the nucleus in circular paths. The size of the nucleus is very small as compared to the size of the atom.
In this model, only certain special orbits known as the discrete orbit of electrons, are allowed inside the atom. While revolving the electrons do not radiate energy. These orbits are called energy levels or shells.
Hope it helps.