2b - group 7 halogens Flashcards
state 4 characteristics of group 7
-coloured vapours
-form ionic salts with molecules
-form molecular compounds with non-metals
-7 electrons in outer shell
state 4 group 7 elements and their states of matter
-fluorine is a pale yellow gas
-chlorine is a pale green gas
-bromine is a dark brown liquid
-iodine is a grey solid
state 2 changes that occur as one moves down group 7
- higher melting points and boiling points
-less reactive
name group 7 of the periodic table.
the halogens
explain why fluorine is in group 7 of the periodic table.
because it has 7 electrons in its outer shell
give the colour and state of chlorine at room temp.
a green gas
what happens to the melting points of the halogens going down the group
the melting point decreases.
explain why iodine cannot displace chlorine from potassium chloride.
because iodine is less reactive than chlorine
why does chlorine have a higher melting point than fluorine?
because there are strong inter molecular forces which need more energy to overcome.
give the charge of ions when halogens react with group 1 metals.
1-
define the term reactivity.
the tendency of a substance to undergo a chemical reaction by losing or gaining electrons.
what are halide ions?
when halogen atoms gain an electron, carrying a 1- charge
