There are many models of atom are present but I told the best models in this post.
It is difficult to understand about atom but it is not impossible, you can understand by the models diagram and all other things. It will helps you a lot.
Introduction to atom
In this time of modern science you can understand about all the things not only about atom,
In now days we can easily understand about what we want to know about but in old days scientists have to face many difficulties during research or study about atom.
There are many scientists that gave various models of atom according to their research and all scientists have their different theories but with the time many scientist gave many theories better than each other.
It is important to realize that a lot of what we know about, the structure of atom has been developed over a long period.
In present’s days we know that the atoms are made up of a positively charged nucleus. In which the negatively charged electrons are present around the nucleus.
However in the past, before the structure of the atom was properly understood, scientists came up with lots of different models or pictures to describe what atoms look like.
Models are mostly simple and easy to understand because mostly peoples can understand about what they want to know, for example
Most of you plays with the toy car in your childhood that are like a model of big real car same as with models of atom.
A model cannot be always be absolute accurate and it is important that we realize this so that we do not build up an incorrect idea about something.
There has been a variety of models of atom. In this article I will be tell about mainly three atomic models and the models are –
Things that you are going to know in this post –
Thomson’s atomic model
After the discovery of electron and positive rays in 1897, most of the people realized atoms are made up of even smaller particles. A scientist named sir J.J. Thomson first of all assumed an atomic model.
According to Thomson’s atomic model, an atom is a sphere of positive charge in which electrons are embedded or distributed.
However the atomic nucleus had not discovered yet. Thomson knew that atom had an overall neutral charge. He thought that there must be something to counter balance the negative charge of an electron.
In this model atoms were known to consist of negatively charged electrons, though Thomson called them ‘’corpuscles”.
The assumption of J.J. Thomson was based on the British dish called plum pudding. In this British dish plum pudding basically it is a desert in which raisins are embedded in dish.
Same as this happens in atom like plum pudding is atom and raisins are electron which are embedded in atoms. Therefore this atomic model called plum pudding model.
Like in India mostly of you ever eat Indian dish kheer. In Kheer you often see that raisins, pista and cashew are present inside the kheer same as with atom.
This model tried to explain two properties of atoms that are –
- Electron are negatively charged particles.
- Atom has no net electric charge
Rutherford’s atomic model
Rutherford analyze the plum pudding model of J.J. Thomson in 1911. Rutherford realize that there is something missing in this model and in atom like he thought that
Electrons are negatively charge but there should be a positive charge present in atom it is impossible to only negative charge present in the atom then he said this model of plum pudding is incorrect.
Then he do a experiment, according to this experiment he take a very thin metal foil (0.00001 cm or 100 mm gold foils) and do bombarding (throwing many particles) of α charged particles obtained from any radioactive elements.
Important things about Rutherford’s experiment
On this thin metal foil and then he observe some important things like as –
- Most of the alpha or α particle pass straight across the foil (as shown in the image)
- Some particles are deflected from their original path.
- One out of the about 20,000 particles returns back to their original path.
On the basis of these observations Rutherford concluded his theory and result related to atomic structure and declared nuclear theory. Like as –
- Most of the portion in an atom is hollow, because most of the alpha or α particles pass through the metal foil.
- Maximum mass and positive charge of an atom is concentrated at the center. This is because of the deviation or returning back of particles with two unit positive charge and 4 amu mass. This center of the atom is called nucleus.
- Nucleus is very small about 10-13 solid and rigid part of an atom.
On the basis of these conclusion, Rutherford assumed the nuclear model of an atom. According to his theory, space excluding the nucleus which contains positive charge and whole mass is empty.
In this hollow space, electrons having negative charge equal to positive charge in the nucleus revolve similar to planets in the space revolves around the sun that is electron revolve in the orbits around the nucleus similar to solar system.
Electrons and the nucleus are held together by electrostatic forces of attraction.
Bohr’s atomic model
Rutherford atomic model is unable to explain completely the stability of an atom, spectrum and distribution of electrons in an atom. There was many researches did with time.
Then a scientist named Niels Bohr came and present this model in 1913. This is the best model in all models of atom.
The Bohr’s model is relatively primitive model of the hydrogen atom, compared to the valence shell atom.
Result of Bohr’s model
Then Bohr did a complete research about the Rutherford’s atomic model and result obtained by the study are –
- It explains the dual nature of electromagnetic radiation.
- Experimental result related to atomic spectrum based on quantized electronic energy level in atoms.
- It is essential to understand certain terms for the study of these laws.
Bohr extended the model of hydrogen to give an approximately model for heavier atoms. This gave a physical image that reproduce many known atomic properties for the first time.
Heavier atom have more protons in it’s nucleus and more electrons to cancel the charge. Scientists are still researching on other models of atom to make models of atom easy in understand.
Basically Bohr’s idea was that each orbit could hold a certain number of electrons. After that orbit is full, the next level of orbit would have to used.
These are the some basic model that gives you a deep knowledge about the structure of atom and about the electrons.
Model is very easy to understand and it is very important to know about the model because it helps you to give a better knowledge as compared to simple theories.
I’m sure you all know that the simple theories are booring and complicated that’s why scientists also make many models of atoms,
Electrons, nucleus and many others to help us in knowing about the atom and science. I’ll cover the answer of all the questions in my next article.
These models are the only thing that makes study of atom easy and interesting. But these models has it’s different rules and laws that makes these models different.
These models of atom are made because with the help of this we can understand atom and it’s structure easily.
We can easily learn with these models of atom. as you see all models you observe that there is a easy to understand diagram on all models. With the help of them you can learn many things about atom.
The some best models of atoms are – Thomson’s atomic model, Rutherford atomic model, Bohr’s atomic model.
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