First nucleus

First nucleus in universe is formed after three minute of Big Bang. 

Before there was nothing matter, except a state of hot and dense energy. After Big Bang due to
  rapid cooling of hot and dense state first nucleus is formed. Then gradually other matter is started to form. Hence, Big Bang is considered as the first step of innitiating our universe.

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Structure of atom

Atom is the unit of any compound or element. It just like the building block, how a lot of breaks arranges altogather builds a building. As same a lot of atom forms an element.

Rutherford at first gives a structure of atom.

Nucleus is the centre of atom. It is a positively charged. The major particles of nucleus is proton and nutron.

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Big Bang

It is a common question from all of the physics researchers that how and from where our existing universe is emerges. What was the structure of primordial universe.

Basically, there was nothing before big bang, but except a hot and dense state. Big Bang is the first step of forming our universe. There had no any matter before big bang. First nucleus of universe is formed after three minute of big bang.

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Black hole

Black hole

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Fundamental force

The fundamental interaction or fundamental force in universe is very complex things today particle physics. In general physics, Force is something exerted on object that tends to move or stop objects motion.

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There exist four fundamental force in universe. These are 

Strong force

Weak force

gravitational force

Electromagnetic force