Topic 7

• Go down halogen group reactivity decreases
• melting and boiling point increase as you go down group7
• hydrogen halides dissolve in water to produce acidic solution
• oxidation is loss of electrons
• more reactive halogen displaces less reactive halogen
• Add alkali metal to water and it disappears and fizzes
• group 1 reactivity increases as you go down group
• alkali metals stored in oil because of very reactive with oxygen
• metal + water —> metal hydroxide + hydrogen
• alkali metals are soft
• metals have lower boiling point as doing down group
• Noble gases are inert and non-flammable
• melting point and density increase down group0
• bond Breaking is endothermic
• bond making is exothermic
• Activation energy - minimum amount of energy needed for particles to react
• catalyst create an alternative pathway and lower Activation energy
• products have less energy than reactants in exothermic reaction
• products have more energy than reactants = endothermic reaction
• Displacement & precipitation is Exothermic
• increase collision = higher temperature, more concentration and increased surface area