Neutron A particle in the atomic nucleus

Neutralization reaction an acid-base reaction. (4.9) Neutron a particle in the atomic nucleus with mass virtually equal to the proton s but with no charge. (2.6)... 

The behaviour of the physical world is controlled by the forces between the particles of which that world is composed. There is a hierarchy of such forces. They range from the relatively weak force of gravity to the strong ones which hold together the particles in the atomic nucleus. Between two neutrons within a nucleus, for instance, the total attractive force is made up of nuclear force to gravitational in the ratio of 1038 to 1. 

Neutrons are found in the atoms nucleus, too. Neutrons are subatomic particles that have no charge, but they have a mass that is almost equal to that of a proton. Since the nucleus contains protons, which have a positive charge, and neutrons, which are neutral, the nucleus of an atom has an overall positive charge. Most of the mass of an atom is concentrated in its nucleus. In fact, the mass number of an element is the sum of the protons and the neutrons in the nucleus of that atom. So, for example, the element chlorine (Cl) has an atomic number of 17, and most chlorine atoms have a mass number of 35. Since chlorines atomic number is 17, this must mean that all chlorine atoms have 17 protons. Because the mass number is equal to the number of protons plus neutrons, chlorine atoms that have a mass number of 35 must have 18 neutrons—because 17 + 18 = 35. 

Neutron a subatomic particle in the atomic nucleus with no charge. 

Nuclear transformation the change of one element into another. (19.3) Nucleon a particle in an atomic nucleus, either a neutron or a... 

Rutherford and others postulated that there must be another type of subatomic particle in the atomic nucleus the proof was provided by another English pltysicist, James Chadwick, in 1932. When Chadwick bombarded a thin sheet of beiylhum with a particles, a very high energy radiation similar to y rays was emitted by the metal. Later experiments showed that the rays actually consisted of electrically neutral particles having a mass slightly greater than that of protons. Chadwick named these particles neutrons. 

James Chadwick was happy to return to England in 1917. He had been studying in Germany at the outbreak of World War 1 and had been imprisoned there for four years. He was broke but alive. Fortunately, his old mentor Ernest Rutherford took him in. His job was to search for the neutral particle that Rutherford believed must exist in the atomic nucleus, a particle he called a neutron. 

The smallest unit having the chemical properties of the element are the atoms. All atoms are made up from a number of elementary particles known as the protons, neutrons, and electrons. The protons and neutrons make up an atomic nucleus at the center of the atom, while the electrons, distributed in electron shells, surround the atomic nucleus. The atoms of each element are identical to each other but differ from those of other elements in atomic number (the number of protons in the atomic nucleus) and atomic weight (their weighted average mass) as listed in the table below. 

An atom Is made up of a nucleus of profons and neutrons, surrounded by a cloud of electrons, proton a type of elemenfary particle that has a positive electrical charge and is found in the nucleus of all atoms, neutron a particle of an atom that has no electrical charge and is found in the nucleus of all atoms. 

Both protons and neutrons are called nucleons, a term that denotes their location in the atomic nucleus. Table 3-1 summarizes the basic facts about our three subatomic particles. 

Nucleon Any subatomic particle found in the atomic nucleus. Another name for either a proton or neutron. 

Besides nuclear charge, atoms also differ in their masses. The mass is determined by the number of protons Z and the number of neutrons N in the atomic nucleus. The total number of nuclear particles, Z + N. in an atomic species is known as its mass number A. 

HADRONS. These are subatomic particles, the strong interactions of which are manifested by the forces lhal hold neutrons and protons together in the atomic nucleus. Hadrons include Ihe proton, the neutron, and pion. among others. These particles show signs of an inner structure, i.e.. they are made up of other panicles, which has led over a period of the last several years to consider the hadrons as combinations of constituents known as quarks. See also Quarks and Particles (Subatomic). 

Only about 300 of the more than 3600 known isotopes occur naturally. The remainder have been made by nuclear transmutation, the change of one element into another. Such transmutation is often brought about by bombardment of an atom with a high-energy particle such as a proton, neutron, or a particle. In the ensuing collision between particle and atom, an unstable nucleus is momentarily... 

The periodic table provides the chemist with a very brief and simple representation of the elements. Recall that most of the mass of an individual atom is contained in the nucleus. In addition, a nucleus contains one or more protons and, with the exception of ordinary hydrogen (1H), one or more neutrons. As discussed in chapter 2, the mass number (A) is an integer and is equal to the number of protons (Z) plus the number of neutrons (N) in the nucleus. It is the number of protons that determines what element a particular atom is. The general term nucleon is used to describe both neutrons and protons, or particles found in the atomic nucleus. 

Neutrons Chargeless particles residing in the atomic nucleus. Neutrons have a mass of 1 amu. 

Alpha decay loss of an alpha particle (nucleus of a helium-4 atom) from the nucleus which results in a decrease in the atomic number by two (two protons) and the mass number by four units (two protons and two neutrons). 

The neutron also is located in the atomic nucleus (except in Hydrogen). The neutron has no charge, and a mass of slightly over 1 amu. Some scientists propose the neutron is made up of a proton and electron-like particle. 

In a survey of forces which bind material systems into their various configurations the first question to arise is that of the interactions in the atomic nucleus itself. To this question only a partial answer can be given. The real components of the nucleus are not definitively known, and the part played by mesons is uncertain, but a reasonable working hypothesis, which accounts for at least some of the facts, is that the bxiilding-blocks consist of neutrons and protons. Between these two kinds of particle an attractive force is postulated, and in opposition to the attraction there is the Coulombic repulsion of the protons for one another. If there are Z protons and N neutrons, the approximate atomic weight A will be given hy A = N- -Z, and the atomic number, or nuclear charge will be Z. 

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