The nucleus is very small, with a diameter of10-15m ~10-/4m, accounting for only 100 billion of the atomic volume, but more than 99.96% of the atomic mass is concentrated in this tiny nucleus. The density of atomic nuclei is extremely high, and the nuclear density is about 10 17kg/m3, that is, if the volume of 1m3 is filled with atomic nuclei, its mass will reach10/4t, that is, 100 billion tons.
When some nuclei undergo fission (the nucleus splits into two or more nuclei) or fusion (the light nuclei combine to become heavy nuclei when they meet), they will release huge nuclear energy, that is, atomic energy (such as nuclear power generation). Without electricity, the whole atom is neutral.
Extended data:
Degree of freedom of nucleus:
1 and π meson degrees of freedom
While establishing the interacting boson model, the nuclear structure theory has made new progress from the study of non-nuclear degrees of freedom in the nucleus. Although the generalized core-shell model represented by the nuclear collective model has achieved some success, it still has some limitations. First of all, these models only reflect the mechanism of nuclear system by analogy from some experimental facts or observed phenomena.
2. Quark degrees of freedom
From the late 1940s to the early 1950s, with the operation of large accelerators in the world, particle physics gradually differentiated from nuclear physics. Since 1960s, particle physics has made a series of remarkable progress. For example, glashow, Salam and Weinberg unified the weak-current interaction in the gauge theory of SU(2)×U( 1) symmetric groups in the early 1970s, which was confirmed directly and indirectly in many aspects.
3.EMC effect
The traditional proton-neutron model of nuclear is very successful in describing low-energy nuclear phenomena, indicating that quark effect or other non-nuclear degrees of freedom in nuclear should be found in high-energy nuclear phenomena.
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