Origin and abundance of the elements, Chemistry

Assignment Help:

 

ORIGIN AND ABUNDANCE OF THE ELEMENTS

The synthesis of elements needs nuclear reactions, of which the most important type is the fusion of two light nuclei to prepare one of higher mass and charge. The attractive strong interaction, which holds neutrons and protons together, operates only over very short distances (around 10-15 m) and is opposed at longer size by the electrostatic repulsion between positively charged protons. To get two nuclei close enough together for fusion needs enormously high energies, which are usually found only at high temperatures (above 107 K) in the interior of stars. Under such conditions the chemical properties of components are irrelevant, as no compounds may exist, atoms being in highly ionized states stripped of their electrons.

 

Gases thrown out by a supernova cool, and can subsequently be incorporated into new stars. The formation of planetary systems can be common in the Universe. Studies suggest that other planets and the Earth formed about the same time as the Sun. While the Sun formed at the center, chemical reactions in the cooler outer parts of the gas concentration produced solid particles, which collected under gravitational forces, first into small bodies known as planetesimals, and subsequently into the planets. In the outer parts of the Solar System temperatures were low enough to form 'ices' of water, carbon dioxide, solid methane and ammonia, which are constituents of the giant planets Saturn and Jupiter.

 


Related Discussions:- Origin and abundance of the elements

Geometrical isomers, Why is geometrical isomers not possible in tetrahedral...

Why is geometrical isomers not possible in tetrahedral complexes having two different types of unidentate ligands? Ans) Tetrahedral complexes do not show geometrical isomerism be

Physical chareterstics of carbonyl compounds, Physical chareterstics of car...

Physical chareterstics of carbonyl compounds Physical state: a. Methanal is a pungent smell gas. b. Ethanal is a volatile liquid and boiling points 294 K. c. Other ald

S block, Uses of plaster of paris

Uses of plaster of paris

Canizzaro rex., Why 2-methyl propanal gives canizzaro Rex.

Why 2-methyl propanal gives canizzaro Rex.

Geopolymer.., i need email tutor who has good background on geopolymer ceme...

i need email tutor who has good background on geopolymer cement to explain it for me such as the geopolymerisation process and fly ash composition by skype or Yahoo or hotmail i ne

The nature of chemical bonding, What is the nature of chemical bonding betw...

What is the nature of chemical bonding between  Cs and F: (1) Covalent (2) Ionic (3) Coordinate (4) Metallic Ans: Ionic

D block elements, Why do Zr and Hf show similar properties?

Why do Zr and Hf show similar properties?

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