Group 7 Flashcards
what type of molecules are halogens
diatomic one pair of electrons held in covalent bond
what happens as you go down the group
Temperature increases to melt/boil and reactivity decreases
what is the physical properties of chlorine
reactive poisonous green gas
what is the physical properties of bromine
- red brown liquid gives of orang vapour, dense
what is the physical properties of iodine
dark grey crystalline solid gives off purple vapour
what is the test for chlorine
If chlorine gas is present, damp blue litmus paper will be bleached white
It may turn red briefly before bleaching, as acids are produced when chlorine comes into contact with water
what happens when metal and halide react
metal halide forms very vigorous reaction
higher up more reactive as electrons attract electron from metal easily
what happens when hydrogen and halide react
hydrogen halide when dissolved in water produce hydrochloric acid
why does reactivity decrease
because only need to gain one electron to form 1- easier it is to attract the more reactive lower down larger atomic radius electron is further away so harder to attract
how is a halogen displacement reaction redox
halogen are reduced and halide ions are oxidised
what does chlorine displace
bromide and iodide
orange and brown
what can bromine displace
iodide
brown
