Atoms

AtomChris Boykin

AtomThe atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons (except in the case of hydrogen-1, which is the only stable nuclide with no neutrons). The electrons of an atom are bound to the nucleus by the electromagnetic force.

Eelectrons : The electrons in an atom are attracted to the protons in the nucleus by the electromagnetic force. This force binds the electrons inside an electrostatic potential well surrounding the smaller nucleus, which means that an external source of energy is needed for the electron to escape. The closer an electron is to the nucleus, the greater the attractive force. Hence electrons bound near the center of the potential well require more energy to escape than those at greater separations. Electrons

Proton: Proton is a subatomic particle with a positive charge and a mass of 1.67262 1027 kg which is 1,836 times the mass of an electron. When the number of protons in the nucleus is equal to the number of electrons orbiting the nucleus the atom is electrically neutral. Proton

Neutron: is a subatomic particle with no electric charge and a mass of 1.67493 1027 kg, greater than that of a proton and an electron. Neutrons and protons are commonly called nucleons. The neutron was discovered in 1932 by the English physicist James ChadwickNeutron

Thomson's atomic theory proposed a model of atom which is known as plum pudding model or Christmas pudding or chocolate chip cookie model. Till the end of the nineteenth century the concept of atom was similar to a small solid billiard ball. In the year 1897 Joseph john Thomson totally changed the view of an atom by discovering electron. Thomsons atomic theory suggested that the atom is not indivisible as it was of smaller pieces electrons and protonsJ.J. Thomsons Atomic Theory

J.J. Thomson.!!!Sir Joseph John "J. J." Thomson, OM, FRS[1] (18 December 1856 30 August 1940) was a British physicist. In 1897 Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, and thus he is credited with the discovery and identification of the electron; and, in a broader sense, with the discovery of the first subatomic particle. Thomson is also credited with finding the first evidence for isotopes of a stable (non-radioactive) element in 1913, as part of his exploration into the composition of canal rays (positive ions). He invented the mass spectrometer. Thomson was awarded the 1906 Nobel Prize in Physics for the discovery of the electron and for his work on the conduction of electricity in gases.John Dalton

John Dalton FRS (6 September 1766 27 July 1844) was an English chemist, meteorologist and physicist. He is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness (sometimes referred to as Daltonism, in his honour).William Cookes

Sir William Crookes, OM, FRS (17 June 1832 4 April 1919) was a British chemist and physicist who attended the Royal College of Chemistry, London, and worked on spectroscopy. He was a pioneer of vacuum tubes, inventing the Crookes tube. Crookes was the inventor of the Crookes radiometer,[1] which today is made and sold as a novelty itemErnest RutherfordErnest Rutherford, 1st Baron Rutherford of Nelson, OM FRS[1] (30 August 1871 19 October 1937) was a New Zealand-born British physicist who became known as the father of nuclear physics.[2] Encyclopedia Britannica considers him to be the greatest experimentalist since Michael Faraday (17911867).[2] In early work he discovered the concept of radioactive half-life, proved that radioactivity involved the transmutation of one chemical element to another, and also differentiated and named alpha and beta radiation.[3] This work was done at McGill University in Canada. It is the basis for the Nobel Prize in Chemistry he was awarded in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances".[4]

Electron Cloud ModelAn atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. ...

Atomic NumberThe number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

IsotopeEach of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.Atomic Mass NumberThe mass number, also called atomic mass number or nucleon number, is the total number of protons and neutrons in an atomic nucleus. Because protons and neutrons both are baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion. ...

Strong Nuclear ForceThe nuclear force (or nucleonnucleon interaction or residual strong force) is the force between two or more nucleons. Its fundamental laws and constants are unknown unlike the Coulomb and Newton laws. It is responsible for binding protons and neutrons into atomic nuclei. The energy released by such binding causes the masses of nuclei to be less than the total mass of the protons and neutrons which form them; this is the energy used in nuclear power and nuclear weapons.[1][2] The force is powerfully attractive between nucleons at distances of about 1 femtometer (f m) between their centers, but rapidly decreases to insignificance at distances beyond about 2.5 fm. At very short distances less than 0.7 fm, it becomes repulsive, and is responsible for the physical size of nuclei, since the nucleons can come no closer than the force allows.Radioactive DecayRadioactive decay, also known as nuclear decay or radioactivity, is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation. A material that spontaneously emits this kind of radiationwhich includes the emission of energetic alpha particles, beta particles, and gamma raysis considered radioactive. Radioactive decay is a stochastic (i.e., random) process at the level of single atoms, in that, according to quantum theory, it is impossible to predict when a particular atom will decay.[1] However, the chance that a given atom will decay is constant over time. For a large number of atoms, the decay rate for the collection is computable from the measured decay constants of the nuclides (or equivalently from the half-lifes).ElementA part or aspect of something abstract, esp. one that is essential or characteristic.

TransmutationThe action of changing or the state of being changed into another form.

Parts Of An Atoms (Model). && The Differences Between Protons, Neutron, And Electron.!!!There are three parts of an atom. These three parts are known as protons, electrons and neutrons. You can tell the difference by:

-Electrons have a negative charge. They are smaller and more numerous than the bigger protons and neutrons. -Protons are positive and are located in the nucleus of an atom, along with the neutrons. Protons are like the name tag of an atom, because the number of protons defines the atom itself. Protons also have what scientists believe another part inside of them called quarks. This fact is not believed by all scientists because they have not seen it themselves or it just might be something else. -Neutrons have no charge because they are neutral. Now, one might ask how did they discover neutrons if they do not have a charge. This question can be answered because of the extra weight in the nucleus of an atom. They also keep the protons in balance because they hold them together inside the nucleus.