Who give the liquid drop model?
Carl Friedrich von Weizsäcker
One of the first models which could describe very well the behavior of the nuclear binding energies and therefore of nuclear masses was the mass formula of von Weizsaecker (also called the semi-empirical mass formula – SEMF), that was published in 1935 by German physicist Carl Friedrich von Weizsäcker.
How is it explained on the basis of liquid drop model?
According to the liquid drop model, the nucleus is assumed to be like a drop of a liquid with certain analogies. As a result, the nucleus takes the dumbbell like shape as is shown, and due to positive charge repulsion on the two ends splits into two fragments hence, forming daughter two nuclei.
What are the uses of liquid drop model?
The liquid drop model is applied to describe some basic properties of atoms, homoatomic molecules, metallic clusters of atoms and fullerene molecules. Equilibrium atomic size, energy and polarizability of the atom are calculated.
What are assumptions of liquid drop model?
Assumptions of the Liquid Drop Model The nucleus consists of incompressible matter. The nuclear force is identical for every nucleon. The nuclear force saturates. In an equilibrium state, the nuclei of atom remain spherically symmetric under the action of strong attractive nuclear forces.
Why do we say that a nucleus behaves like a drop of liquid?
In a stable state, the nucleus is spherical in shape just as the liquid drop is spherical due to the symmetrical surface tension. The nuclear force is short range force, similarly as that of liquid drop in which intermolecular forces are short range forces.
How do you calculate nucleons?
Explanation: Nucleon number is the number of protons plus the number of neutrons.
What is surface energy in liquid drop model?
Surface term: The nucleons at the surface of the ‘liquid drop’ only interact with other nucleons inside the nucleus, so that their binding energy is reduced. This leads to a reduction of the binding energy proportional to the surface area of the drop, i.e. proportional to A2/3 −aS A2/3.
What is the difference between liquid drop model and shell model?
~ Shell Model is same as the atomic model where electrons arrange themselves into shells around the nucleus, whereas The Liquid Drop Model is a description of atomic nuclei in which the nucleons (neutrons and protons) behave like the molecules in a drop of liquid.
What are the similarities between liquid drop and nucleus?
The similarities between drop of liquid and nucleus are as follows: The force that holds the molecules of a drop together is similar to the short-range nuclear force that binds the nucleons in a nucleus. The surface tension forces act on the molecules, so the drop appears spherical in shape.
What are the two kinds of nucleons?
An atomic nucleus is shown here as a compact bundle of the two types of nucleons, protons (red) and neutrons (blue).
Why is iron the most stable nucleus?
It turns out that the most stable atom of all, because it has the largest average binding energy per nucleon, is a particular isotope of iron (iron-56). The nuclei higher up the periodic table are not as stable, which is why radioactive decays, and fission, occur.
Why do liquid drop becomes spherical?
KnowHOW team explains: Water drops, or, for that matter, the drops of any other liquid, are spherical in shape due to a phenomenon called surface tension. In a liquid this acts on the surface of a freely falling drop to minimise its area. This results from the attraction between the molecules in the liquid.
Which is the best description of the liquid drop model?
Liquid-drop model. Written By: Liquid-drop model, in nuclear physics, a description of atomic nuclei in which the nucleons (neutrons and protons) behave like the molecules in a drop of liquid.
How does the liquid drop model of the nucleus work?
Liquid Drop Model of Nucleus. Scattering experiments suggest that nuclei have approximately constant density, so that the nuclear radius can be calculated by using that density as if the nucleus were a drop of a uniform liquid.
How is the Pauli principle used in the liquid drop model?
The Pauli principle also favors nuclear configurations with even numbers of neutrons and protons. In the liquid drop model, this is included by using the even-odd nucleus as a reference and adding a correction term which is positive for even-even nuclei and negative for odd-odd nuclei.
How is the Weizsaecker formula used in liquid drop model?
In the liquid drop model, this is included by using the even-odd nucleus as a reference and adding a correction term which is positive for even-even nuclei and negative for odd-odd nuclei. This strategy for modeling the nuclear binding energy is attributed to Weizsaecker and called the Weizsaecker formula. Weizsaecker formula Index