the periodic table 3.0 / 5 based on 1 rating ? ChemistryThe Periodic TableASOCR Created by: rayanne vitaliCreated on: 05-12-12 20:08 what is periodicity ? is a regular periodic variation of properties of elements with atomic number and position in the periodic Table 1 of 21 what are the three factors that affect ionisation energies ? nuclear charge , distance from the nucleus, electron shielding 2 of 21 what happens to ionisation energies across a period ? general increase across a period 3 of 21 what happens to ionisation energies down a group ? energys decrease down a group 4 of 21 what is the trend in boiling points across a period ? increase between 1 -4 , sharp decrease between 4-5 , low boiling points 5-8 5 of 21 why is there a sharp decrease in boiling points between groups 4 and 5 ? Because the structure if the elements change from giant structures to simple weak molecular forces 6 of 21 name 3 physical properties of group two elements they have reasonably high melting and boiling points , they are light metals with low densities , they form colourless compounds 7 of 21 what happens to a group to element in a reaction ? it becomes oxidised 8 of 21 what happens to group to elements when they react with water ? they form hydroxides with the general formula M(OH)2, and hydrogen gas is formed. 9 of 21 what is thermal decomposition ? the breaking up of a chemical substance with heat into at least two chemical substances 10 of 21 what happens to group 2 oxides when they react with water ? they form a solution of a metal hydroxide 11 of 21 what happens when a group 2 hydroxide reacts with water ? they form alkaline solutions 12 of 21 what happens when a group 2 carbonate is decomposed ? it forms a metal oxide and CO2 13 of 21 name 2 physical properties of group 7 elements they have low melting/ boiling points , they exist as diatomic molecules 14 of 21 what happens to halogens in a reaction ? they become reduced 15 of 21 what is a displacement reaction ? a reaction in which a more - reactive element displaces a less reactive element from an aqueous solution of the latters ions 16 of 21 what is disproportionation ? the oxidation and reduction of the same element in a redox reaction 17 of 21 what are trends of group 7 elements and compounds? less reactive down the group , and elements react with metal to form ionic halides with an X- ion. 18 of 21 how do you test for halides ? unknown halide is dissolved in water , then an aqueous solution of silver nitrate is added.. a coloured precipitate is formed 19 of 21 what halides form what colour precipitates ? chloride= white , Bromide= cream , iodide= yellow 20 of 21 if you cannot judge the colour of a halide precipitate , what could you do ? add aqueous ammonia , different halides have different solubilities 21 of 21
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