Topic 6 Flashcards
As alkalines go down the group:
- melting / boiling point decreases
- reactivity with water + oxygen increases
- density increases
- ram increses
Lithium reacting with water:
- fizzing
- skates on top of water
- until dissolves
- releases hydrogen
Sodium reacting with water:
- more vigorously than lithium
- red flame
- forms ball on water
- dissolves faster
Potassium reacting with water:
- lilac flame
- violent fizzing
why do elements further down the group more reactive?
- as elements go down the group there’s more shielding
- the electron in the outermost shell gets further away from the positive nucleus
- the further away it is, the weaker the forces of attraction is so it’s easily lost
halogen properties
- becomes darker down the group
- non - metal
- toxic
- corrosive
- boiling / melting point increases
florine
gas
pale green
chlorine
gas
greenish yellow
bromine
liquid
red/brown
Iodine
solid
gray (sublimes to purple gas)
At
solid
black (radioactive)
halogens uses
disinfectants:
they can kill all microorganisms
e.g. swimming pools
alkalines react with
oxygen to form metal oxides
water to form metal hydroxides
chlorine to form metal chlorides
Nobel gases
are inert as they have full outer shell of electrons so doesn’t need to loose or gain any
helium
used in balloons and airships
LESS DENCE than air so float
not flamable
argon
used inside filament bulbs because its inert so stops the metal reacting with oxygen
also
welding
stops hot metal reacting with oxygen in the air
neon
used in signs because produces coloured light when current passes through it
halogens colours
fl - gas pale green
cl- gas greenis yellllow
bro - liquid red- brown
io - solid grey sublimes to purple gas
as - solid black radioactive
