Chemistry C4 4.5 / 5 based on 3 ratings ? ChemistryGCSEOCR Created by: Mollie DerhunCreated on: 29-01-13 18:05 ATOMIC STRUCTURE & ATOMIC BONDING The Nucleus is made up of protons and neutrons The electron has a charge of -1 The proton has a charge of +1 The neutron has a charge of 0 Metals form positive ions as they lose electrons Non-metals form negative ions as they gain electrons Isotopes are elements that have atoms of the same atomic number but different mass numbers Ionic bonding happens because of the transfer of electrons from metals to non-metals Sodium chloride and magnesium oxide form giant ion lattices as their ions attract 'Dot and Cross' models can be used to represent the ionic bonding in compunds 1 of 4 THE PERIODIC TABLE AND COVALENT BONDING Non-metals combine by sharing electrons Carbon dioxide and water are simple molecules with weak intermolecular forces between the molecules Carbon dioxide and water have low melting points as the intermolecular forces are weak The period to which an element belongs is the same as the number of occupied electron shells 2 of 4 GROUPS The group number is the same as the number of electrons in the outer shell Rubidium and caesium are group 1 metals which react violently with water to give off hydrogen and make an alkaline solution Group 1 metals have similar properties as they all need to lose one electron from their outside shell Flame tests can be used to identify the presence of lithium, sodium and potassium Chlorine is a green gas, bromine is a brown liquid and iodine is a grey solid If a group 1 metal reacts with a group 7 non-metal the word equation for the formation of a metal halide can be constructed 3 of 4 METALS AND WATER Copper compounds are often blue Iron (II) compounds are often light green Iron (III) compounds are often orange/brown The thermal decomposition of transition metal carbonates results in the metal oxide and carbon dioxide being made Cu₂+ ions react with sodium hydroxide to make a blue soild in a precipitation reaction Metals have high boiling points due to their strong metalic bonding Superconductors conduct electricity with little or no resistance Drinking water is purified by filtration, sedimentation and chlorination Sulfates in water can be tested using barium chloride Halides can be tested using silver nitrate 4 of 4
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