In the periodic table, the elements are listed in order of increasing atomic number Z. The number of electrons in each elementвЂ™s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior.

The configuration of these electronsВ follows from the principles of quantum mechanics. The chemical properties of the atomВ are determined by the number of protons, in fact, by number and arrangement of electrons. Knowledge of the electron configurationВ of different atoms is useful in understanding the structure of the periodic table of elements.Д®very solid, liquid, gas, and plasma is composed of neutral or ionized atoms.

The electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. The periodic table is a tabular display of the chemical elements organized on the basis of their atomic numbers, electron configurations, and chemical properties. It should be noted that all of these decay pathways may be accompanied by the subsequent emission of gamma radiation. Many other rare types of decay, such as spontaneous fission or neutron emission are known. Unstable isotopesВ decay through various radioactive decay pathways, most commonly alpha decay, beta decay, or electron capture. If there are too many or too few neutrons for a given number of protons, the resulting nucleus is not stable and it undergoes radioactive decay. As a result, as the number of protons increases, an increasing ratio of neutrons to protons is neededВ to form a stable nucleus. Neutrons stabilize the nucleus, because they attract each other and protons, which helps offset the electrical repulsion between protons.

There are only certain combinations of neutrons and protons, which forms stable nuclei. These two forces compete, leading to various stability of nuclei. The neutron has a mean square radius of about 0.8Г—10в€’15 m, or 0.8 fm, and it is a spin-ВЅ fermion.ДЄtomic nuclei consist of protons and neutrons, which attract each other through the nuclear force, while protons repel each other via the electric forceВ due to their positive charge. It has no electric chargeВ and a rest mass equal to 1.67493 Г— 10в€’27 kg-marginally greater than that of the proton but nearly 1839 times greater than that of the electron. In the universe, neutrons are abundant, making up more than halfВ of all visible matter. Rubidium-87 is composed of 37 protons, 50 neutrons, and 37 electrons.ДЄ neutronВ is one of the subatomic particlesВ that make up matter. Rubidium-85 is composed of 37 protons, 48 neutrons, and 37 electrons. 85Rb is the most common isotope, having a natural abundance of approximately 72%. Of these, 87RbВ is very slightly radioactive, decaying by beta decay with a half-life of 4.9Г—10 10 years. Rubidium occurs in 2 natural isotopes: 85Rb and 87Rb. Mass numbers of typical isotopes of RubidiumВ are 85 87. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. The difference between the neutron number and the atomic number is known as the neutron excess: D = N вЂ“ Z = A вЂ“ 2Z.ДЇor stable elements, there is usually a variety of stable isotopes. NeutronВ number plusВ atomic numberВ equals atomic mass number: N+Z=A. The total number of neutronsВ in the nucleus of an atom is called the neutronВ numberВ of the atom and is given the symbol N. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10 -19В coulombs. Total number of protons in the nucleus is called the atomic numberВ of the atom and is given the symbol Z. RubidiumВ is a chemical element with atomic number 37 which means there are 37 protons in its nucleus.

I number of neutrons