Earth, Science

Assignment Help:

Earth

How do we describe the 'big ball' on which we live? Seen from space, it appears as a bluish-white sphere. Its wealth of plant and animal life, snow covered peaks, blue oceans and white clouds make the Earth a beautiful planet. Human beings have explored it extensively. Yet, the first hand knowledge of  the Earth is limited to a thin shell of  rock and water extending to a few kilometres below the surface, and to the atmosphere above. However, using indirect methods, such as the study of waves generated during earthquakes, scientists have been able to picture the Earth's interior. without ever seeing or sampling it. We will now briefly describe the current scientific knowledge about the Earth. 

 

1094_Earth.png

The Earth's  atmosphere has been studied extensively with  the help of ground based experiments, aircraft, rockets and balloons. Though it  is not divided  into distinct layers, it-is helpful to think of  the atmosphere in this way. The troposphere, nearest to the surface,  is made up of  78 per cent nitrogen and 21 per cent oxygen, with water vapour, carbon dioxide, neon and argon making up most of  the remaining one per cent. It has an average temperature of about 16°C at sea level and-  16OC near its top. The stratosphere, coming next contains ozone and has a temperature ranging from -  16OC to -4OC.  This ozone layer absorbs the harmful UV radiations fron, the Sun,  thus protecting us from them. The carbon dioxide in the Earth's atmosphere traps heat and makes it warmer through the greenhouse effect. Were it not for this, the Earth's surface temperature would be much lower and it would always be covered with ice.


Related Discussions:- Earth

Water Polution, what is the solution of the water polution

what is the solution of the water polution

White lipped tree frog, how does reproduction help the white lipped tree fr...

how does reproduction help the white lipped tree frog survive

Softening water with chemicals, Softening water with chemicals Try mak...

Softening water with chemicals Try making suds with a half test tube of hard water and a few drops of soap solution. Next boil a same sample and again try to make suds by usin

Water pressure changes with depth, Water pressure changes with depth Us...

Water pressure changes with depth Use the funnel and manometer which you made in the last experiment. Fill a tall glass jar or pail with water. Calculate the pressure just belo

Science project, i dont know how to set up my science board

i dont know how to set up my science board

Explain the microscopical examination of urine, Explain the Microscopical e...

Explain the Microscopical examination of Urine By microscopical examination, the pus cells, RBC and cast cells are found if the infection is present. Microscopical examination

Surfaces of colloidal fractions of clay minerals, Surfaces of colloidal fra...

Surfaces of colloidal fractions of clay minerals The surfaces of colloidal fractions of clay minerals and humus are responsible for the cation and anion  exchanges between soil

Hard and soft water in cleaning, Hard and soft water in cleaning Prepar...

Hard and soft water in cleaning Prepare two samples of dirty cloth. Wash one in soft water with soap unless it is clean. Wash the other cloth in hard water for the similar leng

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd