Periodicity

Part 1 i) PERIODICITY The periodic put off shows trends in the properties of the genes. cyclicity refers to trends or recurring variations, in chemical element properties with pitch magnitude nuclear human activity. Periodicity is ca utilise by regular and sure variations in element nuclear structure (chemguide, 2010) The periodic table is the arrangement of elements match to nuclear number. This means, the number of protons each element has in its nub. Dmitri Mendeleev position a chart of the then 63 k straightwayn elements by increasing miteic weight and uniform properties in 1869. The on-line(prenominal) periodic table is arranged by atomic number, tumid groups of elements with similar physical properties, and Horizontal periods of increasing atomic number, creating the S, P, D, and F blocks. These Periods and Groups indicate varying trends in elements: * Ionization recruit (kJ.mol-1) * nuclear radius (?) * Electro negativity (Pauling sca le) * Electron Affinity (kJ.mol-1) * Trends in negatron configuration can also be seen in groups * The number of electrons in an elements outer shell * Melting points * oxidisation states * Atomic mint (in cm3) ii) IONIZATION ENERGY Ionization crowd is the energy needful to abate 1 mole of electrons from 1 mole of atoms in the vaporous phase to form a positive ion (cation). (Last years divide notes, 2010) * Na(g) -------> Na+(g) + e- * Energy used = 496kJ.mol-1 This shows the first ionization energy of Sodium. Ionization energy is quoted in units of kilojoules per mole (kJ.mol-1). The second ionisation energy is much higher(prenominal) than the first because the electron is now being removed from a positive Ion. Energy is needed to remove an electron from an atom because there is an attraction between the positively charged nucleus and the negatively char ged electron. The visit the ionization ener! gy the easier the change happens. The first Ionization energy depends...If you want to get a full essay, order it on our website: BestEssayCheap.com

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