why does not electron fall to nucleus? and why is energy of electron negative?

Answer 1

First part: because of the high speed of electrons, they spin around the nucleus with enough energy that they won't be pulled in. This is (almost) the same as how the moon orbits the earth without falling into it. The forces involved are different (gravity as opposed to electrical attraction), but the result is the same.

(This is not entirely true, but is the easiest way to think about it. In reality, the electrons have a probability of being in certain places. Being in the nucleus violates a fundamental law of quantum mechanics, called the Heisenberg Uncertainy Principle: "You can never know both the speed of an electron and its location." If you know that an electron is in the nucleus, then you also know it has a velocity of zero. According to quantum mechanics, this is fundamentally impossible, and so cannot happen).

Second part:
It has to do with quarks and leptons. Quarks are tiny particles that, combined, make up protons and neutrons. A proton has two up quarks and one down quark - and combined, that makes one positive charge unit.

Leptons are quarks' cousins. They have a charge of either one or negative one. Electrons are a kind of lepton, and have a charge of negative one.

Answer 2

hi ii is a stability that the electrons have with one yet another in the atom. to boot because of the fact the nucleus.they are attracted yet saved at distance by potential of the make up of the nucleus because it is not only one particle. yet made out of different factors. which entice and repel the electrons. hydrogen is the least complicated atom besides the incontrovertible fact that this is electron is saved in this is orbit.

Answer 3

When I was a physics student, I was continually frustrated by the inability of physics to explain why. It did OK at explaining what would happen, but never did it explain why it would happen...whatever "it" was.

We are still al long way from explaining why. For example, we do not know why electrons have a negative charge. They just do. Sure they are leptons and all leptons have negative charge, but that's what...not why. [See source.]

Why do leptons have negative charge, no one really knows. What we do know is that, if they did not, the universe would not have formed the way it did. But, then again, that's what...not why.

Contrary to the implication of your first question, electrons do fall into the nucleus now and then. But perhaps not the way you meant. In fact, electrons are described by their probability density functions around the core of an atom. These functions are something like the Normal or Bell shaped curve, but only in four dimensions (including time) rather than two.

The shell like volume around the core of an atom where it is most dense is the volume where an electron is most likely to be found. The location of the highest probability volume is predicated on the energy level of the electron. Higher energy electrons are more likely to be found closer in than lower energy ones. But regardless of the energy level, the highest probability, most dense volume is ouside the core; which means electrons are most likely to be found outside the nucleus.

But, and this is a big BUT, like a 2D Bell probability density curve, that high density volume trails off as lower density tails in all directions and some of those tails of the curve actually pass through the nucleus of the corresponding atom. In other words, there is a small but definite probability that some electrons could be found within the core of an atom. To be sure that probability is small and the time spent within the nucleus would be correspondingly small, but it is possible.

So you are right in the sense that the highest probability of finding an electron is ouside the core. But you are incorrect by saying they do not ever fall to the nucleus because, probabilistically speaking, they occasionally do.

Answer 4

i am answering only the second part of your question as you have got answers to your first question.
the energy of the electron is negative is not a correct statement. the mechanical energy is comprised of 2 parts. the potential energy and the kinetic energy. the potential energy by definition is equal to zero at infinity and is less than 0 at any conceivable position.so the electron at infinite orbit has 0 p.e.. but the kinetic energy of the electron is always positive. if we sum these 2 up we get a quantity that is -ve. so the total mechanical energy is negative.

Answer 5

Because it is revolving around it. While the electron is to the "North" of the nucleus, heading "Eastward", the attraction draws it "Southward". By the time it has turned 90° and is heading "South", it is now to the "East" of the nucleus with the attraction acting "Westward". And so on. To experience this for yourself, tie something heavy to a piece of string and swing it in a circle. You will feel tension in the string, indicating that some force is acting on the object to keep it moving in a circle.

The charge (*not* the energy; energy is *always* positive) on an electron is negative by historical accident. Someone once decided that one kind of electrical charge -- that would later be discovered to be due to a shortage of electrons -- was to be called "positive", and the other kind -- that we now know to be due to a surplus of electrons -- was to be called "negative".

Answer 6

it all goes to the theory of de broglies where electeron path is like a wave not a circle so attraction of charge decreases. well there is no exact answer to it.
as the proton is positive so to counter balance the atom neutral charge electron is negative.

Answer 7

Hai
Electrons never fall in to the nucleus because they are repelled by the heavy positive charge of the nucleus.The best known and smallest elementary particle, apart from the neutrino, is the electron. An electron can have a positive or a negative charge Qe. The electron with a positive charge is called positron. When we mention the electron we mean the negative charged particle.so "THERE IS NO FACT IN SAYING THAT IT IS -VE"