ATOM | Atom Particles
What is an ATOM ? | How small is an ATOM?
Have you ever broken a chalk before obviously we all must have done this sometimes in our life can you further break this into a small piece yes this can be further divided and it will be so tiny that we won’t be able to see it through our naked eyes such tiny elements which cannot be divided further are known as atoms atoms are made up of three sub-atomic particles protons neutrons and electrons let us understand each of them individually with the help of a simulator here this orange colored ball represents the protons whereas the grey balls represent the neutrons and blue colored balls represent the electrons now protons are positively charged ions and present in the nucleus electrons are negatively charged and revolve around the nucleus and neutrons have no charge hence a neutral in nature the path on which the electrons revolve around the nucleus is called the orbit there are four types of orbits namely s p d and f today we are going to learn only about the s and p orbits the inner dotted line represents s orbits s orbits have a capacity of two electrons [Music] let’s add one more electron to s orbits you can see that electron is not going in s orbits that means only two electrons can revolve around the nucleus in s orbit now outer dotted line that is p orbits have a capacity of 8 electrons so only 8 electrons can revolve around the nucleus in p orbits likewise d and f orbits have their own capacity to fill the electrons now let’s build an atom first let’s add one proton what did you observe here hydrogen atom starts forming when we fill the atom with subatomic particles the corresponding element will appear or start forming you can see here that the atom shows a positive charge why is this so this is because the proton has a positive charge therefore the atom shows a positive charge now as we all know that all the elements are neutral in nature so here we want a neutral atom how will we get a neutral atom we must add electrons here but how many electrons we can add for one proton one electron is added because in the nucleus the number of protons and electrons are always the same see atom is neutral now and we can see that the net charge is zero and the mass number is one but what is the role of neutrons here neutrons help to stabilize the nucleus since the nucleus in this case is stable so hydrogen need not include neutrons only hydrogen is an exception where the neutron is not required in the nucleus let’s see what will happen when we add one neutron to the nucleus of hydrogen element see nucleus is still stable but the mass number is changed because neutron and proton have their own masses if we change the number of protons or neutrons the mass number of an atom will also change here hydrogen atom has mass number two if you remove the neutron the mass number will be one the mass number is the number of protons plus the number of neutrons let us add one more electron proton and neutron to the atom [Music] have you observed that the element has changed and it becomes helium with mass number 3 and a stable nucleus let’s add one more proton to the nucleus what happens here you can see here the element changes to lithium but why the nucleus is unstable because here neutron is not added let’s add neutron until the nucleus becomes stable see the nucleus is stable now here atom shows 1 plus charge but we want a neutral atom so what we can do is we must add one electron to the atom because to neutralize the plus one charge minus one charge is needed here we got a neutral atom and mass number six because three protons and three neutrons are present in the nucleus if we increase the number of protons electrons and neutrons gradually we can get different elements with their mass numbers scientists discovered that the electrons are uncertain which means the position of an electron is not fixed it is difficult to identify the distance of each electron from the nucleus so scientists found some areas where the electrons may be present around the nucleus this area is called the electron cloud if we increase the number of electrons in an atom the area of the cloud will also increase hydrogen helium lithium and more such elements are arranged in a particular structure with their symbol this structure is called the periodic table.