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support@askiitians.com, 4 years ago

Grade:Upto college level

10 Answers

Shefali Mohapatra

33 Points

4 years ago

Electrons are revolving around the nucleus with a certain speed. Due to which they expirience an outward centrifugal force balancing the force if attarction by the nucleus. Hence they revolve in the same orbit withour falling into the nucleus.

Vatsal Bhuva

16 Points

4 years ago

This is because the electron can only move across shells only when it's corresponding energy changes. Different orbits in an atom are associated with different energy levels. If the electron LOSES energy and equals the energy of any other previous shell, it will move to that shell (if the electron is not in K shell) and if it GAINS energy such that it's energy is equal to the energy associated with any other orbit after it, then the electron will move to that shell (it the electron is not in outermost shell)

Prakhar Gupta

36 Points

4 years ago

Combine a proton and an electron, and charge-wise, you've made a neutron. That's what should happen if electrons fell into a nucleus. A proton's mass is 1.6726 x 10^-27 kg, and an electron's mass is 0.00091 x 10^-27 kg, but a neutron's mass is 1.6749 x 10^-27 kg. So the mass of an electron and proton combined is still nowhere near enough for a neutron. If you want them to combine together, you would need to add energy, or mass, or both.

Moreover, according to the Heisenberg uncertainity principle, a particle as tiny as the electron cannot be regarded as having either a definite location or momentum. The Heisenberg principle says that either the location or the momentum of a quantum particle such as the electron can be known as precisely as desired, but as one of these quantities is specified more precisely, the value of the other becomes increasingly indeterminate. It is important to understand that this is not simply a matter of observational difficulty, but rather a fundamental property of nature. What this means is that within the tiny confines of the atom, the electron cannot really be regarded as a "particle" having a definite energy and location, so it is somewhat misleading to talk about the electron "falling into" the nucleus.

Paul Lexi McHughe

20 Points

4 years ago

According to Heisenberg’s uncertainty principle,

$\Delta x\cdot \Delta p \geq \frac{\bar{h}}{2}$

where delta x is uncertainty in position, delta p is uncertainty in momentum and h bar is reduced planck’s constant. this means that there is a mimimum uncertainty for either the position or momentum.

If we examine the uncertainty in the position,

$\Delta x \geq \frac{\bar{h}}{2\cdot \Delta p}$

if uncertainty in momentum goes to zero, that is, the electron goes to rest, then the uncertainty in the position goes to infinity.

If we examine the uncertainty in momentum and if the uncertainty in position goes to zero, that is, the elctron collapses into the nucleus, the uncertainty in momentum goes to infinity.

Since atoms have a finite size, the mere uncertainty will prevent the atoms from collapsing in on themselves. This is what keeps the electrons in motion around the nucleus.

Nikolas Tesla

27 Points

4 years ago

Well s state electron do peak at the nucleus and their wavelengths interfere [electrons are in fact not particles to collide with the proton in the nucleus but a superpositiom of both waves and particles ,wave particle duality ] well in classical physics Electrons that move in an orbit around the nucleus change direction, thus accelerate And therefore emit electromagnetic radiation (loose energy) and therefore should get closer to the nucleus and collide into it , the atoms being highly unstable and collapse in seconds(fraction of seconds)but electrons are just not particles to do so ...they have their wavefunctions ! And electrons in fact do collide with the proton in the nucleus at time of electron capture during radiative decay and the electron and proton fuse into a neutron (like in strange stars to form strange matter) why this happens so rarely is that electrons can only jump 3d orbitals not orbits as they require specific energy levels they can't achieve.. also this only happens when there are many protons with an atom so the outerones are free to react with the electron .... this is what Neil bohr found out from max plank's quantum theory..this all is based on quantum mechanics and on principles like Heisenberg's uncertainty principle which states we can't find the exact location and momentum...and many of us might be unaware if this as what we k is just classical NEWTONIAN mmechanics which Is not correct half the time in the REAL world of quantum particles

Nikolas Tesla

27 Points

4 years ago

MY ANSWER IS A BIT LONG BUT WORTH READING AND I HOPE YOU WILL UNDERSTAND IT EASILY ....

HUH …

THIS IS KRUTARTH FROM OTHERS CLASS 10 BINDERS

THANK YOU AND HAVE A NICE DAY

HOPE IT HELPS

Jatin Soni

36 Points

4 years ago

According to physics the revolving particles undergo acceleration and should radiate energy and fall into nucleus. However, according to Neil Bohr's postulates, electrons revolve in some special orbits called descrete orbits and while revolving in these orbits, they don't radiate energy. Hence they don't lose energy and fall into nucleus.

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Classical physics has no answer to that particular question. The fact that the electrons don't collapse into the nucleus is one of the key results that resulted in the overthrow of classical physics . Classical mechanics follows: If the electrons were orbiting like say the moon orbits the Earth then they would be constantly radiating energy, this would eventually lead to the decay of the orbit and the electron would fall into the nucleus. It doesn't ergo classical mechanics is wrong.

In Quantum physics an electron orbit is more of a probability of locating an electron at a given point in space than any implied motion of said electron. This and the discreet nature of energy in the quantum world means that there is no where lower for the electron to go once it is in the ground state.

Jatin

Chandra21

DHARA SACHIN SHAH

15 Points

4 years ago

electrons revolve around the neucleus and that too in a circular motion...so it experiences two forces--
1. Nuclear charge
2. Centrifugal force

the centrifugal force pushes it outside while the nuclear charge is pulling it in......that means that the 2 forces are equal and opposite....that means they canccel out the effect of each other...hence the electrons are stable in the same orbit and do not spiral around to collapse...

by – Dhara Shah

Chandra 20

Ushasi Ghosh

28 Points

4 years ago

The electron doesn't fall into the nucleus because if it would have fallen into the nucleus then the atom would not exist. This is the reason Bohr has told that the electron revolves around the nucleus in a definite orbit.

DHRUVI SACHIN SHAH

17 Points

4 years ago

electrons revolve around the neucleus in a circular motion due to electromagnetic force between electron and proton binding it. the nuclear charge pulls it in and centrifugal force due to revolution, push it out side, being in opposite direction and equal force, electron remain in orbit and not falls into the nucleus.

Dhruvi shah

Chandra 20