Periodic Table Flashcards
what is a group?
vertical column
what is a period?
horizontal row
why do elements in the same group have the similar chemical properties?
have the same number of electrons in outer shell`
why are metals good conductors of electricity?
allow charge to pass through them
what is the acid-base character of metals?
they are basic
- dissolve to form alkaline solutions - pH>7
what is the acid-base character of non-metals?
they are acidic
- dissolve to form acidic solutions - pH
what does inert mean?
does not react easily
why are noble gases inert?
they have full outer shell (stable)
use of helium
balloons
use of neon
advertising signs
use of argon
lightbulbs
use of krypton
lasers
use of xenon
photographic flashes
physical properties of alkali metals
- conductors of electricity and heat
- soft - easily cut with knife
- low density (float on water)
chemical properties of Li, Na, K
- shiny surfaces when cut but instantly tarnishes
- burn in air to form white, solid oxides (have to be kept under oil)
- react with water to form metal hydroxide and hydrogen
observation of lithium reaction with water
- moves around surface
- bubbles of gas
- gets smaller and smaller; eventually disappears
observation of sodium reaction with water
- moves around surface
- bubbles of gas
- melts into shiny ball
- gets smaller and smaller; eventually disappears
observation of potassium reaction with water
- moves around surface
- bubbles of gas
- melts in ball
- burns with lilac flame
- gets smaller and smaller; eventually disappears
why is potassium the most reactive out of lithium, sodium and potassium?
- has more shielding
- greater distance between outer electron and nucleus
- lower attraction force
use of lithium
battery anode
use of sodium
salt (in sodium chloride)/ street lights
use of potassium
fertilisers
use of rubidium
vacuum tubes
trend for density of alkali metals
increases down group
trend for BP/MP of alkali metals
decreases down group
what is the state and colour at room temperature of chlorine?
- gas
- green
what is the colour of aqueous chlorine?
- pale green
- when diluted, colourless
what is the state and colour at room temperature of bromine?
- liquid
- red-brown (evaporated to form brown gas)
what is the colour of aqueous bromine?
- orange
- when diluted, yellow
what is the state and colour at room temperature of iodine?
- solid
- black (sublimes when heated form purple gas)
what is the colour of aqueous iodine?
brown
what is hydrogen chloride, HCl?
colourless gas at room temperature
what is hydrochloric acid, HCl?
hydrogen chloride dissolved in water
reaction of hydrogen and chlorine
forms hydrogen chloride when exposed to UV light
reaction of hydrogen and bromine
hydrogen and bromine vapour will react when heated
reaction of hydrogen and iodine
hydrogen and iodine vapour will react when heated but not fully
reaction of chlorine and hot iron wool
- wool glows brightly
- forms brown smoke
- brown solid formed
reaction of bromine and hot iron wool
- wool glows less brightly
- forms brown smoke
- brown solid formed
reaction of iodine and hot iron wool
- wool glows even less brightly
- forms brown smoke
- brown solid formed
trend for reactivity of halogens
less reactive down group
