The Difference between Noble gases, Alkali metals and Halogens

The Difference between Noble gases, Alkali
metals and Halogens
Groups Noble gases Alkali metals Halogens
(Group 18) (Group 1) (Group 17)
Elements Helium, Neon, Lithium, Sodium, Fluorine, Chlorine,
Argon, Krypton, Potassium, Bromine, Iodine,
Xenon & Radon Rubidium, Astatine
Cesium, Francium
Atomic Radius Increases when Same Same
going down the
group
Reason: The
number of shells of
the elements
increases when
going down the
group
Melting point -Very low -Very low -Low
& Boiling point -Increases when -Decreases when -Increases when
going down the going down the going down the
group group group
-Held by Van der -Metallic bond -Force of attraction
Waals force becomes weaker become stronger
Density -Low Same Same
-Increases when
going down the
group
Reactivity -Very stable -Increases when -Decreases when
-Does not receive, going down the going down the
accept or share group group
electrons with Reason: Reason:
other elements It is easy to lose It is hard to gain one
-Inert gases one valence valence electron to
electron to achieve achieve stable
stable electron electron arrangement
arrangement because the atomic
because the atomic size increases when
size increases going down the