Question

Approximate age of the earth (in million years) is:
A. 3600
B. 4600
C. 7200
D. 6000

Answer 1

Hint:-Earth is the third planet from the sun after Mercury and Venus. Only this planet in the solar system is known to have a living organism. About 71% of the earth is made up of water and the remaining consists of land. Most polar regions are covered with ice. The inner core of the earth is made up of the earth’s magnetic field. Earth has the presence of a natural satellite i.e. moon.

Complete solution:
The formation of the earth and its life is a debating topic. Many theories explained the formation of the earth and life on earth. The solar system first formed like a cloud of dust, a mixer of gases, rocks, etc. There were about more than 92 elements that made this cloud. The Big Bang led to the formation of two important gases helium and hydrogen. After this, there was the formation of lithium gas. The hydrogen and helium fused and formed the carbon which then became the foundation for life on earth. Then later calcium formed which became part of the bone. Over millions of years ago, the large dust cloud exploded and formed groups. The mass started concentrating in the middle and this gave rise to the sun. The smaller concentrate of mass formed the planets and the Earth. At first, the earth was in a molten state. As the years passed it started to cool and formed a solid mass that was able to hold the water.Later the atmosphere formed and it was inhabitable for life.
The options given in the question are discussed below:
A. 3600- about 3millions years ago the earth was 3-4 degrees warmer than the present. The north part was not filled with ice. The global sea level was high and later it turned to glaciers.
B. 4600- the present formation of the earth which is suitable for the life forms evolved about 4000 million years ago. The hotter part of the earth’s crust cooled at this period.
C. 7200- about 7200 million years ago the Earth was still not formed. The components that made the earth were forming the cloud.
D. 6000 – The cloud containing a mixture of gases, dust exploded and led to the formation of stars and other planets.
The approximate age of the earth( in million years ) is 4600 million years, thus option (B) is correct.

Note:- Big bang theory is the theory that explains how the universe originated. According to this theory, our universe originated about 13.7 billion years ago. Universe formed due to the massive expansion that formed like a gigantic balloon. Life on earth formed millions of years after the formation of the earth that is about 3.7 billion years ago.