INTRODUCTION TO NUCLEAR REACTION: The main features of nuclear reactions include radioactive decay, nuclear fission and nuclear fusion. Radioactive decay: Energy is released in a radioactive decay in the form of the kinetic energy of the particle emitted (α and β), the kinetic energy of the daughter nucleus and the energy of the gamma-ray photon that may accompany the decay. The energy involved may be calculated by finding the mass defect of the reaction. The energy released is the energy equivalent of the mass defect of the reaction. Nuclear fission: Nuclear fission is the process in which a large nucleus breaks into two smaller nuclei that are almost equal in mass.
Neutrons, Protons and electrons are all sub-atomic particles. In relative mass, we always think of protons and neutrons in having a mass of 1 and electrons a mass of 1/1840, which shows that electrons are considerably smaller than protons and neutrons, and only make up a small part of the atom. The amount of protons and neutrons added together is the relative atomic mass, and this is the main structure of the atom. 2. The arrangement of particles in an atom Protons and neutrons make up the main, dense, central nucleus in the centre of the atom.
Seventy five percent of the table is made up of metals, and a couple of the columns on the right of the table have gases. There are only two elements that are liquids- mercury and bromine. Column 1 contains the alkali metals, which suddenly combust when exposed to air or water. Columns 3-12 are the transition metals, which contain heavier atoms, which are more flexible in how they organize their electrons. Column 17 is made up of the more reactive gases- the halogens.
Describe the differences between protons and electrons The difference between protons and electrons is that protons are positively charged and that elections are negatively charged. Another difference is that protons are in the nucleus and electrons circle the nucleus in shells outside the nucleus. What is the difference between the mass number and the relative atomic mass of an element? The difference between the mass number and the atomic mass is that the mass number is the number of protons and neutrons in the nucleus and the relative atomic mass is the mass of an atom. Distinguish between an element and a compound with 2 examples for each An element is a substance that cannot be broken down into any simpler substances.
The electrons of an atom are bound to the nucleus by the electromagnetic force. A group of atoms can remain bound to each other by chemical bonds based on the same force, forming a molecule. An atom containing an equal number of protons and electrons is neutral; otherwise it is positively or negatively charged and is known as an ion. An atom is classified according to the number of protons and neutrons in its nucleus the number of protons controls the element, and the number of neutrons determines the isotope of the element. A molecule is an electrically neutral group of two or more atoms held together by chemical bonds Molecules are recognized from ions by their lack of
The atomic masses of two isotopes of cobalt are 59 and 60. a) What is the number of protons and neutrons in each? • The protons are the same otherwise it wouldn't be cobalt = 27 So the remainders are neutrons = 32 or 33 b) What is the number of orbiting electrons in each when the isotopes are electrically neutral? • Electrons = protons = 27, if electrically
Astronomy 10 Chapter 11 1. Both used to be normal stars but the white dwarf ran out of hydrogen, they are both subjected to gravitational theories. A Neutron star is a fluid of neutrons, as hot at its surface as the inside of the sun and has a greater magnetic field. 3. Because its density is so high, neutrons spin in the same way that electrons do so must obey the Pauli Exclusion Principle.
David Kemp OCR Chemistry A Unit 1: F321 Atomic Structure (a) describe protons, neutrons and electrons in terms of relative charge and relative mass; Proton +1 1 Neutron 0 1 Electron -1 1/2000 Relative Charge Relative Mass (b) describe the distribution of mass and charge Within an atom; Positively charged Nucleus containing most of the mass, surrounded by atomic shells with orbiting electrons of negative charge and negligible mass. (c) describe the contribution of protons and neutrons to the nucleus of an atom, in terms of atomic (proton) number and mass (nucleon) number. The atomic number of the nucleus, also the proton number, shows the number of protons in the nucleus. It also defines the element. The number of neutrons added to the number of protons is the nucleon number or mass number.
INTRODUCTION Gadolinium is a shiny silvery white, malleable, ductile, metallic, rare earth element which is located in group 3, f-block, period 6 and classified in the series of lanthanides in the elements of periodic table and has 27 isotopes whose half-lives are known with mass numbers from 137 to 164. This element is considered a rare earth element because there is such a small amount of it, and it is not found often in its simplest form. It was discovered in 1880 by Jean Charles de Marignac where it was extracted in from the mine located in Ytterby in Sweden, but it was isolated from metal oxide in 1886 by Lecoc de Boisbaudran who named it after the Finnish Chemist Johan Gadolin who discovered the first rare earth element in 1794. Gadolinium
Nuclear Power is produced by controlled (non-explosive) reactors. They convert the thermal energy released from nuclear fission. When uranium and plutonium are enriched, it undergoes nuclear fission. It releases kinetic energy and gamma radiation. This whole process is called a nuclear chain reaction.