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Neutrons, Neutrons, Neutrons

I understand that  in large elements which contain many protons, there exist too many neutrons to extend the strength of strong nuclear force and to overcome the electromagnetic repulsion force of protons. Such elements are stable in this way. But, I read that element with too many neutrons are also unstable. WHY ?  What I know is that too many neutrons can’t enlarge the electromagnetic repulsion force and can increase the strong nuclear force, so they even make the nucleus more stable . What’s wrong with me ? Please!

 

Asked a student

 

English: Animation of the mechanism of the nuc...

 

How protons became closer during Big bang process?

English: Schematic representation of a nucleus...
English: Schematic representation of a nucleus as an ensemble of neutrons and protons (Photo credit: Wikipedia)

I know that strong nuclear force is a short-ranged force. So, I would like to know how protons became closer during Big bang process. Is it because of very high temperature and pressure during this ?
Please explain me.
Thanks in advance.

(thatoekhant)

In nuclear fusion the nucleons (protons and neutrons come closer because of their high energies. When they come closer to each other in the order of distances of fermi (10^-15 m) nuclear force – the strongest force in nature, comes into play

… Awaiting responses

Usage of energy in nuclear fission and fusion

I read in a biographic book about Albert Einstein that the energy produced from burning materials is much less than the energy stored in them (the authored suggested the book itself as an example – he wrote that it can power a ship for about 100 years).
I would like to know how much of the energy of a material is used in nuclear fission and fusion.

Asked Avishag

Answer:

Nuclear explosion
Nuclear Explosion (Source: WIkiPedia)

Energy obtained by burning a substance is meagre compared to the energy contained in it. According to Einstein’s mass energy relation (E=mc2), the energy released by converting 1 gram of any substance completely into energy = 0.001 (mass) x 300,000,000 x 3,00,000,000 (square of velocity of light).

But, in nuclear reactions, the entire mass is not converted into energy. The tremendous energy liberated during a nuclear explosion is the result of a small portion of the mass of nucleus undergoing the reaction getting converted into energy.

For example, when a uranium 235 atom undergoes nuclear fission the enrgy liberated is 200 MeV = 200 x 1.6 x 10 -19 J

In 235 g of U-235 there are 6 x 1023 atoms.

So if that much of U-235 atoms undergo fission, the energy liberated will be about 1,00,00,000 J.

Hope that you might have had an idea of it.

Nuclear fusion Videos

Nuclear Fission and Fusion

H Manishankar Asked:

which releases more energy?fusion or fission?

Ans:

per fission energy is more for fission, Per unit mass energy released is very much more for fusion

 

Mani again:

ok..bt our nuclear weapons are not powerful enough .. their energy is infinitesimally smaller than d energy released in natural process like earthquake volcano

Ans: Nuke weapons are targeted and sufficient to produce local destruction

Geothermal Energy

p.tejaswini asked

“Why is geothermal energy an alternative source of nuclear energy?”

There is some problem with the doubt you asked. It is correct to say “Geothermal energy and Nuclear energy are alternative sources of energy

Sun is the ultimate source of energy for earth. The energy of fuels, wind energy, water energy, food – all these are derived from sun. But Geothermal energy and nuclear energy are not derived from solar energy.

GeoThermal Energy Links for Reference

http://www.renewableenergyworld.com/rea/tech/geothermal-energy

http://www.geos.iitb.ac.in/geothermalindia/pubs/geoweb.htm

See a diagram of Geothermal plant

Geo Thermal Energy
Geo Thermal Energy

The centre of the Earth is around 6000 degrees Celsius – easily hot enough to melt rock. Even a few kilometres down, the temperature can be over 250 degrees Celsius if the Earth’s crust is thin. In general, the temperature rises one degree Celsius for every 30 – 50 metres you go down, but this does vary depending on location

In volcanic areas, molten rock can be very close to the surface. Sometimes we can use that heat.

Geothermal energy has been used for thousands of years in some countries for cooking and heating.

The name “geothermal” comes from two Greek words: “geo” means “Earth” and “thermal” means “heat”.

Read More on Geothermal Energy Here

Formation of Heavier Elements

H. Manishankar (KV Pattom) Asked

Question: Iron is the heaviest element that can be formed by nuclear reactions in a star.So how the heavier elements after iron were formed?And could there be further heavier elements out there in the cosmos?

Answer:

Nuclear fusion inside a star is not the only process my which new elements are created. There are many others too.

During a supernova explosion many unpredictable nuclear transmutations occur, fusing elements and forming heavier elements.

But however, the amount of elements heavier than iron is less.

It’s a good idea to think back (say from the time of BigBang)

Every explosion has a consequent implosion resulting in creation of heavier elements

Remember that birth and death of stars are taking place everyday in some part or other of the universe. The earlier stars had relatively lighter elements in their core. As they die, the remains form part of other stars and other celestial bodies thereby forming heavier elements in the universe.

(I don’t claim that this is a complete answer. Visitors are requested to suggest amendments to this Answer via comments)

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