Atomic Structure and Nuclear Reactions: Key Concepts

Dalton's atomic theory: The matter is made up of extremely small particles, indivisible and indestructible called atoms. / Each chemical element has all different but identical atoms of other elements quimics. / Dalton Based on the chemical compound is formed by the union of atoms of different elements always the same type and the same proportion. Chemical Element: A substance that can not be decomposed into other more simple because it consists of a single type of atom. Compost: A substance that can be decomposed into others are made easier since most pet atoms of element types. Plum pudding model: the atoms are formed by electrons with negative charge are distributed in a sphere of matter of positive charge so that the overall atom is electrically open. Rutherford model: atoms are composed of protons and neutrons electrons. / In every atom the number of protons and electrons the same way that the atom is electrically neutre. / The protons and neutrons elnucli together are very small and the electrons revolve around a much larger space in the crust called electronica. atomic number Z, which is the number of protons has a atom. mass number A, is the total number of particles that are the nucleus of an atom, ie, the sum of protons and neutrons. Isotopes: atoms are those that have the same atomic number but different mass number. Relative atomic mass of an element: is the weighted average of the masses of isotopes of these natural elements.Es multiplied by the atomic mass and the result abunancia joins with others, then divided by 100. Radioactivity: Some radioisotopes showed radioactive isotope called because the kernels was unstable and had just desintegranse. types of radiation: alpha radiation, () are helium nuclei formed by two neutrons and two protons. / beta radiation: () electrons are emitted at high speed. / gamma () radiation is similar to light or X-rays but with much more energy. Half-life: The time it takes for half the nuclei desintegrarse initial radioisotopes. nuclear fission: The cores are broken and released with this large amount of breakage energy. Nuclear fusion: Occurs when small nuclei join together to form more massive nuclei with off while a large amount of energy