Noble gases + Alkali Metals

Noble Gases

group 0 or 8, helium, neon, argon and more

properties of noble gases

* unreactive because they have full outer shells and are reluctant to share electrons


* don’t easily form molecules because their atoms have a stable arrangement of electrons
* all have 8 electrons In outer shell (full) except helium which has 2
* odourless and colourless
* low chemical reactivity
* monatomic (exist as single atoms)

uses of noble gases

* helium for balloons


* neon lights (can pass electric current through them)
* medical applications (lasers)
* useful for protection but not for anything else

Alkali Metals

Group 1, lithium, sodium, potassium etc

properties of alkali metals

* soft (atypical for metals) because there is only 1 electron in outer shell, can be cut with a knife


* low melting, going down the group it decreases
* low densities (less dense than water so the first 3 lithium, sodium and potassium can float on water)
* shiny, conducting, malleable, ductile, highly reactive, insoluble

uses of alkali metals

* lithium = batteries, lubricating greases, air purification, and aluminium production
* pure sodium = sodium-vapour lamps provides highly efficient light
* All of the metals in group one react vigorously with water to create an alkaline solution and hydrogen
* react with oxygen to create an oxide

what happens to the alkali metals as you go down the periodic table

* melting point increases because they get bigger and need more bonds which need more energy to break
* become more reactive = trying to lose an electron and its further form the nucleus and there are more electrons in between, shielding it

oxygen + lithium

burns to give a white solid, becomes lithium oxide

oxygen + sodium

sodium oxide, burns with a lilac flame to give a white solid

oxygen + potassium

potassium oxide, burns with yellow-orange flame to give a white solid

chlorine + lithium

lithium chloride, burns with red flame to give a white solid

chlorine + sodium

sodium chloride, burns to give a white solid

chlorine + potassium

potassium chloride, burns to give a white solid

water + lithium

fizzes, melts, floats on water, becomes lithium hydroxide+ hydrogen

water + sodium

sodium hydroxide + hydrogen, fizzes, melts, floating on surface, may be a lilac flame

water + potassium

melts, fizzes more, floats on water, may be a yellow-orange flame, becomes potassium hydroxide+ hydrogen

oxidation

loss of electrons, whatever lost electrons is oxidised and is therefore called the oxidant

reduction

gain of electrons, whatever gained electrons is reduced and is therefore called the reductant

RedOx

both a reduction and an oxidation during a reaction (gain and loss of electrons)