IGCSE›Cambridge IGCSE Chemistry›Mind mapsGroup I PropertiesCambridge IGCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsThe alkali metalsFirst column of the periodic tableForm alkaline hydroxides with waterLose their outer electron → +1 ionsStored under oil to avoid air and moisturePhysical propertiesSoft, cut with a knifeSofter down the groupStill good conductors of electricityTrends downMelting point decreasesDensity increasesReactivity increasesLarger atoms → weaker metallic bondingGroup Ithe alkali metalsLiNaKRbCsReaction with waterMakes a metal hydroxide and hydrogen2 Na+2 HX2O→2 NaOH+HX2\ce{2Na + 2H2O -> 2NaOH + H2}2Na+2HX2O2NaOH+HX2Vigour: Li < Na < KWhy more reactive?Outer electron further from nucleusMore shielding from inner shellsOuter electron easier to loseExam tipsPredict Rb and Cs by extending the trendSay lose electrons, never gainExplain trends using atomic structure