The day of judgement and what will happen that day?

 The day of judgement and what will happen that day? 

It is part of faith of every believer to believe in the day of judgement. A person cannot be a true believer if he or she does not believe in the day of Qiyaamah. 

Allah says in Quran, 

 Al-Baqarah 2:8

وَمِنَ ٱلنَّاسِ مَن يَقُولُ ءَامَنَّا بِٱللَّهِ وَبِٱلْيَوْمِ ٱلْءَاخِرِ وَمَا هُم بِمُؤْمِنِينَ 

English - Sahih International

And of the people are some who say, "We believe in Allāh and the Last Day," but they are not believers.

So among men who  say we believe in Allah and the last day, but are not indeed believers. 

There are ten signs that will make one know of the hour. 

Hudhaifa b. Usaid al-Ghifari reported:

Allah's Messenger (ﷺ) came to us all of a sudden as we were (busy in a discussion). He said: What do you discuss about? They (the Companions) said. We are discussing about the Last Hour. Thereupon he said: It will not come until you see ten signs before and (in this connection) he made a mention of thesmoke, Dajjal, the beast, the rising of the sun from the west, the descent of Jesus son of Mary (Allah be pleased with him), the Gog and Magog, and land-slides in three places, one in the east, one in the west and one in Arabia at the end of which fire would burn forth from the Yemen, and would drive people to the place of their assembly.

Sahih Muslim 2901 a. 

And on the day of qiyaamah, this earth will change. 

Allah says, 

Al-Anbiya 21:104

The Day when We will fold the heaven like the folding of a [written] sheet for the records. As We began the first creation, We will repeat it. [That is] a promise binding upon Us. Indeed, We will do it.[1]

That day is a great day.

Allah says,

Al-Hajj 22:1

O mankind, fear your Lord. Indeed, the convulsion of the [final] Hour is a terrible thing.

Al-Hajj 22:2

On the Day you see it every nursing mother will be distracted from that [child] she was nursing, and every pregnant woman will abort her pregnancy, and you will see the people [appearing] intoxicated while they are not intoxicated; but the punishment of Allāh is severe.

That day the sight of people turns blue.

Allah says,

Ta Ha 20:102

The Day the Horn will be blown. And We will gather the criminals, that Day, blue-eyed.[1]

The day all relations will be cut 

Allah says,

Al-Mu'minun 23:101

So when the Horn is blown, no relationship will there be among them that Day, nor will they ask about one another.

May Allah guides and protects us from the agonies of that day. Aamiin