The structure of atom based on the studies of different scientists.
Dear Student,
There are various structure of atom are given:
1.) The Plum-Pudding Model of an Atom
According to Thomson's atomic model:
a. An atom consists of a positively charged sphere with electrons embedded in it.
b. The negative and positive charges present inside an atom are equal in magnitude Therefore, an atom as a whole is electrically neutral.
2.) Rutherford model of Atom.
Rutherford's findings were contrary to his expectation. He observed that:
1. Most of the fast-moving alpha particles passed straight through the gold foil.
2. Some particles were deflected through the foil by small angles.
3. One out of every 12000 particles rebounded, ie, they got deflected by an angle of 180".
What Rutherford Concluded from His Observations
Rutherford then carefully studied his observations and made the following conclusions.
1. Most alpha particles passed through the gold foil without any deflection. This indicates that most of the space inside an atom is empty
2. Very few particles suffered a deflection from their path. This means that positive charge occupies very little space inside an atom.
3. Only a small fraction of particles underwent a 180° deflection. This shows that the entire positive charge and mass of an atom are present within a very small volume inside the atom.
Hence based of his conclusion.
1. An atom consists of a nucleus at its centre and all the protons are present inside this nucleus.
2. Electrons reside outside the nucleus and revolve around the nucleus in well-defined orbits.
3. The size of the nucleus is very small as compared to the size of the atom. As per Rutherford's calculations, the is 10 times smaller than the atom.
4. Since the mass of the electrons is negligible as compared to the mass of the protons, almost all the mass of the atom is concentrated in its nucleus.
3.) Bohr's Model of an Atom
The postulates of Bohr's model of an atom are as follows:
1. Only certain special orbits,known as discrete orbits of electrons, are allowed inside the atom.
2. While revolving in the discrete orbits, the electrons do not radiate energy.
3. An electron can jump from one orbit to another by absorbing or emitting a fixed amount of energy in the form of radiation.
Bohr named these orbits as energy levels. These orbits (or shells) are represented by the letters K, L, M, N. numbers n= 1, 2, 3, 4.
Bohr's model of an atom explains how:
There are various structure of atom are given:
1.) The Plum-Pudding Model of an Atom
According to Thomson's atomic model:
a. An atom consists of a positively charged sphere with electrons embedded in it.
b. The negative and positive charges present inside an atom are equal in magnitude Therefore, an atom as a whole is electrically neutral.
2.) Rutherford model of Atom.
Rutherford's findings were contrary to his expectation. He observed that:
1. Most of the fast-moving alpha particles passed straight through the gold foil.
2. Some particles were deflected through the foil by small angles.
3. One out of every 12000 particles rebounded, ie, they got deflected by an angle of 180".
What Rutherford Concluded from His Observations
Rutherford then carefully studied his observations and made the following conclusions.
1. Most alpha particles passed through the gold foil without any deflection. This indicates that most of the space inside an atom is empty
2. Very few particles suffered a deflection from their path. This means that positive charge occupies very little space inside an atom.
3. Only a small fraction of particles underwent a 180° deflection. This shows that the entire positive charge and mass of an atom are present within a very small volume inside the atom.
Hence based of his conclusion.
1. An atom consists of a nucleus at its centre and all the protons are present inside this nucleus.
2. Electrons reside outside the nucleus and revolve around the nucleus in well-defined orbits.
3. The size of the nucleus is very small as compared to the size of the atom. As per Rutherford's calculations, the is 10 times smaller than the atom.
4. Since the mass of the electrons is negligible as compared to the mass of the protons, almost all the mass of the atom is concentrated in its nucleus.
3.) Bohr's Model of an Atom
The postulates of Bohr's model of an atom are as follows:
1. Only certain special orbits,known as discrete orbits of electrons, are allowed inside the atom.
2. While revolving in the discrete orbits, the electrons do not radiate energy.
3. An electron can jump from one orbit to another by absorbing or emitting a fixed amount of energy in the form of radiation.
Bohr named these orbits as energy levels. These orbits (or shells) are represented by the letters K, L, M, N. numbers n= 1, 2, 3, 4.
Bohr's model of an atom explains how:
- the electrons are arranged and distributed in the extra-nuclear space of the atom.
- the atom attains stability due to the presence of energy levels around the nucleus, in which electron revolve without radiating energy.
- each energy shell can accommodate only a fixed number of electrons.
- the filling of a shell begins only when the preceding shell has been completely filled.
- this gives the atom a shell-like structure.