Editing Atomic nucleus

[[Category: Physics]]
== Explanation ==
An atomic nucleus is the center of an [[atom]], made up of [[proton|protons]] and [[neutron|neutrons]]. These are together known as nucleons. The protons and neutrons in a nucleus are held together by the [[nuclear force]], which is a remnant of the strongest fundamental force in nature, the [[strong interaction]].
== Frequently Asked Questions ==
=== Why electrons don’t fall into the nucleus due to attraction? ===
[[Electron]]s tend to stay away from the nucleus because it would violate the [[uncertainty principle]]. If the electron is confined inside a space as small as the nucleus, then its position and momentum could be determined, which is impossible. So that doesn’t actually happen when you try to confine an electron inside a nucleus. According to the uncertainty principle, the energy of the electron will increase as it moves closer to the nucleus. This increases the momentum uncertainty and tends to push the electron away from the nucleus, battling the electrostatic force. The point at which these two cancels out each other will be the electron’s stable configuration in an atom. But there is a special type of decay called as the beta plus decay, where a proton-rich nucleus would absorb an electron to decay itself into a neutron by emitting a positron and a neutrino.

=== What happens when you split the atomic nucleus? ===
[[Nuclear fission]] happens. When the atomic nucleus is split, a tremendous amount of [[energy]] is released, forming two lighter nuclei in the process. A well-known example of a fissile element is [[uranium]] <sup>235</sup>U, which when bombarded with neutrons split into two lighter nuclei. The total mass before splitting is higher than that of the combined mass of the two nuclei and any neutrons emitted. This difference is mass will be the energy of the fission reaction, and it will be enormous. When the emitted neutrons are made to bombard more <sup>235</sup>U nuclei, there will be a [[chain reaction]] that keeps on splitting more <sup>235</sup>U nuclei, exponentially releasing immense amounts of energy.

=== How could the atomic radius of the atomic nucleus be defined? ===
The density of the atomic nucleus is usually concentrated towards the centre where the nucleons exist. An approximate radius of that dense region can be found by using the formula - '''R = R<sub>0</sub>A<sup>1/3</sup>''', where '''R<sub>0</sub>''' is 1.2 fm, and '''A''' is the [[Atomic_mass#What.27s_the_difference_between_atomic_mass_and_mass_number.3F|atomic mass number]]. Some specific cases like the [[halo nucleus]] of [[lithium]], the radius of the nucleus will be higher, and hence this formula fails. In such cases experimental methods like x-ray [[spectroscopy]] are used.