IGCSE›Oxford AQA IGCSE Chemistry›Mind mapsGroup 1Oxford AQA IGCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsPropertiesLow density: Li, Na, K float on waterSoft, cut with a knifeShiny when cut, tarnish quickly in airWith non-metalsForm ionic compounds1 electron in outer shell, lost easilyForm +1 ionsWhite solids, colourless solutionsNa+ClX2\ce{Na + Cl2}Na+ClX2 gives NaClGroup 1the alkali metalsLiNaKWith waterMetal + water → metal hydroxide + hydrogen2 Na+2 HX2O→2 NaOH+HX2\ce{2Na + 2H2O -> 2NaOH + H2}2Na+2HX2O2NaOH+HX2Hydroxides give alkaline solutionsHence the name alkali metalsTrendReactivity increases down the groupOuter electron further from nucleusOuter electron more easily lostReactions more vigorousExam tipsObservations: fizzing, moving or floating, flameGroup 1 reactivity increases downGroup 7 is the opposite