Groups 1, 7 and 0 GapFill

Group 1 elements are called the  metallogensmetalliumsalkali metalsreactant metalsmicrometalsnoble metals and react with oxygen, chlorine and water. Their reactivity  is comparable throughout the groupincreases down the groupdepends largely on their physical statedecreases across a perioddecreases down the groupincreases across a period. These metals share many properties; for example, they are all fairly  strong-smellingelasticcolourfulbrittletoxicmalleable.

Group 7 elements are known as the halogens. A more reactive halogen  solidifiesreplacesovercomesdissolvesincorporatesdisplaces less reactive halogens in a solution. Halogens form  pathogeniccarcinogenicacidicradioactivebasicsterile solutions when they dissolve in water and are often used as  catalystsdisinfectantscoolantselectrolytesfertiliserslubricants.

In a common chemical test,  heliumbrominechlorineiodinecarbon monoxidenitrogen turns litmus paper white.

Halides can form coloured precipitates with silver nitrate, but at room temperature and pressure they each have their own appearance:  heliumfluorineiodinebromineastatinechlorine is an orange-brown liquid,  heliumiodinechlorinefluorineastatinebromine is a dark purple/black solid, and  astatinechlorinefluorinebromineheliumiodine is a pale yellow/green gas.

Group 0 elements are known as the  alkali gasestransition gasesnoble gasesunreactantsnon-metallic gasesneon gases and do not usually react. They are  colourlesshardelectrically conductivemagneticflammabledense, and their boiling point increases down the group.