groups, rate and reactions Flashcards
what are the group one metals know as
alkali metals
what are the group one metals
lithium, sodium, potassium, rubidium, casesium, francium
what do all alkali metals have
one outer electron, so they have similar chemical properties
what are group ones physical properties
low melting and boiling points
very soft - can be cut with a knife
what do all alkali metals form
ionic compounds
are group one metals reactive and why
very as they really loose the single outer electron, so its easier to loose as it’s only weakly attached to the nucleus so needs less energy to remove it
what do reactions with cold water produce
a hydroxide and hydrogen gas
what happens when you put alkali metals in water
they react vigorously
what happens to the reactivity as you move down the group and why
it increases as the out electron is lost more easily in the reaction, reaction becomes more violent
e.g. lithium will move around the surface vigorously
sodium and potassium do the same however they also melt in the heat
what are group 7 elements know as
halogens
examples of group 7 elements
fluorine, chlorine, bromine, iodine, astatine
chemical properties of group 7
7 electrons in their outer shells, similar chemical properties
exist as diatomic molecules, sharing one pair of electrons in a covalent bond
physical properties of group 7
as you go down group 7 the melting and boiling points increase
what is chlorine at room temp
fairly reactive, poisonous, green gas
what is bromine at room temp
poisonous red / brown liquid which gives off orange vapour
what is iodine at room temp
dark grey crystalline solid which gives off purple vapour
what is the test for chlorine
using damp blue litmus paper, if chlorine is present, it will bleach the paper and turn white
how does reactively change as you go down group 7 and why
decreases as it gets harder to attract the extra electron to fill the outer shell when it’s further away from the nucleus
what can halogens react with
metals and hydrogen
how do halogens mix with metals and what do they form
vigorously and form salts called metal halides
what happens during a halogen displacement reaction
a more reactive halogen will displace a less reactive one
what is a displacement reaction
where a more reactive element pushes out a less reactive element from a compound