Atomic structure and periodicity 0.0 / 5 ? ChemistryThe Periodic TableA2/A-levelAQA Created by: champion1607Created on: 15-05-18 19:24 Define relative atomic mass Ar Average mass of an atom of an element on a scale where an atom of carbon-12 is 12 1 of 18 Define relative molecular mass Mr Average mass of a molecule on a scale where an atom of carbon 12 is 12 2 of 18 Name the four processes in mass spectrometry Ionisation, acceleration, ion drift and detection 3 of 18 What are the two procedures to convert a solution into cations Electro-spray ionisation and electron impact ionisation 4 of 18 What accelerates the cations and why is it important that they are at the same kinetic energy An electric field, it is important so the lighter ions will drift quicker 5 of 18 What do the lines and their height represent on a mass/charge graph Each line represents a different isotope of the element and the height tells you the abundance 6 of 18 Electrons fill up the lowest energy sub shells first expect from one exception?? 4s sub shell has a lower energy level and fills before 3d 7 of 18 When transition metals become ions which sub shell loses electrons first? 4s 8 of 18 Name the four elemental blocks of the periodic table s, d, p and f 9 of 18 Name the two metal exceptions to the sub shell theory and explain why Chromium and copper donate one of their 4s electrons to the 3d sub shell to be more stable 10 of 18 Define first ionisation energy Energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous ions 11 of 18 What factors affect ionisation energy? Nuclear charge, atomic radius and shielding 12 of 18 Why is there big jumps in ionisation energies during successive ionisation A new shell is broken into so an electron is lost from a shell close to the nucleus, this can be used to tell what groups elements are om 13 of 18 Describe the two main trends in ionisation energy Ionisation energy decreases down a group and increases across a period 14 of 18 Why does ionisation energy decrease down a group? Extra shielding, weakened nuclear attraction and larger atomic radius 15 of 18 Why does ionisation energy increase across a period? Increased number of protons, stronger nuclear attraction and no extra shielding 16 of 18 Why, despite the trend, is the ionisation energy for Al lower than Mg? Al outer electron is in a 3p orbital which is further away from the nucleus and shielded by the 3s2 orbitals. making it easier to loose an electron 17 of 18 Why, despite the trend, is the ionisation energy for S lower than P? In S the electron is being removed from an orbital containing 2 electrons, the repulsion between these electrons makes it easier to lose 18 of 18
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