If  you see closely you can see the Ant-Man

Have you watched the movie ant-man? It is one of my favorite movies of all times. The best part is when ant-man reaches the sub- atomic level.

What will it feel to reach the size of an atom? Let me bombard your imagination with a rough size of an atom. A billion carbon atoms lined up in a row would be about one foot long. Now, Imagine.

Let's keep this topic aside for a moment and talk the now, shall we? As small as atoms are,  we now know they are not the smallest components of matter. Atoms can indeed be cut into smaller pieces and some of those pieces can be cut even further.

Don't take this image seriously, this is just imagination!

If we look inside an atom we will see a nucleus which has a positive electric charge. Outside the nucleus, there is a cloud of electrons which has negative electric charge. Opposite charges attract one another which holds the atom together.

If we imagine enlarging the nucleus until it becomes the size of a golfball the electron cloud would be over two miles wide. The electron cloud is as much as 1,00,000 times larger than the nucleus. Guess who is the dominating member of the atom family? It is the nucleus!! The nucleus contains almost all of the atom's mass - technically about 99.97% of the whole mass.

Inside an atom

It takes energy to "cut" an atom into pieces - to pull electrons away from the nucleus - but now that's easy to do. With a little more effort we can pull nuclei apart. Nuclei are composed of protons which have a positive electric charge and neutrons which have a zero charge. Rule Of Thumb ➔➔ "Each nucleus must have at least one proton so that its positive charge will attract electrons."

The number of protons in an atom's nucleus is its most important characteristic - Its Element Number. There are over 100 elements in the periodic table, each with a different physical and chemical properties. 

Can you spot Gold and Lead?

Gold is element number 79 with 79 protons in its nucleus. Lead, element number 82 with 3 more protons than gold.See what a difference three little runts make.

The number of neutrons is generally similar to the number of protons, but it can vary. Two atoms with the same number of protons but a different number of neutrons, are the same element and have the same chemical properties, But are different Isotopes.

The most common elements have relatively light nuclei and many of these have equal numbers of protons and neutrons. Carbon has 6 of each, Nitrogen has 7 of each and Oxygen has 8 of each. In heavy nuclei, neutrons outnumber protons. In Their most common Isotopes Iron has 30 neutrons or 26 protons, while Uranium has 146 neutrons and 92 protons.

Generally, atoms have the same number of protons and electrons and therefore they are neutral - having zero net electric charge and atoms which are not electrically neutral i.e. have a different number of protons and electrons are called ions.

Normal hydrogen has the smallest one proton and zero neutrons. A rare but important isotope of hydrogen is deuterium. Its nucleus contains one proton and one neutron while it's the smallest atom, hydrogen accounts for 92% of all atoms and 74% of all atomic mass in the universe. 

Helium is the element number 2, its normal isotope has two protons and two neutrons, helium accounts 7.5% of all atoms and 24% of all atomic mass.

Our Sun is composed of Helium and Hydrogen. (Check if you want)

Together hydrogen and helium make up almost everything we see in the universe. They account for 99.8% of all atoms and 98% of all atomic mass in the universe.

There's altogether a different story ongoing on Earth. About 10% of the ocean is hydrogen but less than 0.2% when it is looked up in the Earth's interior.

Helium is almost totally absent on Earth.


Fun Fact ➔➔ 

Helium was discovered on the Sun and then only on Earth.



But Akshat, you ask, What are we made up of? It's totally different than the composition of Earth, Stars, and Universe as a whole. By mass we are 65% Oxygen, 18% Carbon, 10 % Hydrogen, 3% Nitrogen, 1.5% Calcium, 1.2% Phosphorus and 1.3% other elements.

Congratulation you have survived another lesson of Science. Good Going. You are indeed a fast learner.