From BCIT.ca: The alkali metals show a decrease in melting points and boiling points due to the weaker metallic bonds between atoms as their size increase down the group.
From AUS-e-TUTE: melting point decreases down the Group as the elements become less metallic in nature
From okstate.edu: As one goes down the Periodic Table, the metallic radius of alkali metals increases. The increase in radius results in much decreased attractive forces between atoms within the liquid metals, resulting in a decrease in heat of vaporization and boiling points [and melting points] because less heat is needed to separate atoms from the liquid [or solid] state within the larger alkali metals. See Web Links to the left for the original sources.
All alkali metals are found to be very soft and they have low melting and boiling points. Alkali metals have low binding energy in the metal crystal lattice as these atoms have only one valence electron. This results in the formation of metallic bonds which are not very strong. Also, alkali metals melting and boiling points decrease down the group.
Francium has a melting point of about 27°C (81°F) and a boiling point of approximately 677°C (1251°F). Francium is a highly reactive alkali metal that is rare in nature and is typically found in trace amounts.
Alkali metals are very reactive, not dense or hard metals, monovalent, with low electronegativities, with low melting and boiling points, react violently with water, form strong bases, etc.
Alkali metals belong to Group 1 of the periodic table. They are highly reactive and readily lose their outermost electron to form positive ions. Alkali metals have low melting and boiling points. They are soft and can be easily cut with a knife. Alkali metals include elements such as lithium, sodium, and potassium.
There is no relation ship. They have the lowest ionization energies.
Low melting and boiling point
All alkali metals are found to be very soft and they have low melting and boiling points. Alkali metals have low binding energy in the metal crystal lattice as these atoms have only one valence electron. This results in the formation of metallic bonds which are not very strong. Also, alkali metals melting and boiling points decrease down the group.
Alkaline earth metals do not exist , only alkali earth metals
Some examples of metals with low melting and boiling points include mercury, cesium, and gallium. These metals have melting and boiling points significantly lower than traditional metals like iron and copper.
Francium has a melting point of about 27°C (81°F) and a boiling point of approximately 677°C (1251°F). Francium is a highly reactive alkali metal that is rare in nature and is typically found in trace amounts.
In Group 1 (alkali metals), the melting and boiling points decrease as you move down the group due to the increase in atomic size and metallic bonding. In Group 7 (halogens), the melting and boiling points increase as you move down the group due to the increase in atomic size and London dispersion forces.
Alkali metals have weaker metallic bonding due to their larger atomic size and lower charge density compared to alkaline earth metals. This results in lower melting and boiling points for alkali metals because less energy is required to overcome the forces holding the metal atoms together. Additionally, alkali metals have only one valence electron, making it easier for them to lose this electron and transition into a liquid or gaseous state.
Alkali metals are very reactive, not dense or hard metals, monovalent, with low electronegativities, with low melting and boiling points, react violently with water, form strong bases, etc.
sodium
The melting point of alkali metals is low.
Alkali metals belong to Group 1 of the periodic table. They are highly reactive and readily lose their outermost electron to form positive ions. Alkali metals have low melting and boiling points. They are soft and can be easily cut with a knife. Alkali metals include elements such as lithium, sodium, and potassium.
Th reactivity of alkali metals increases from the top of Group 1A to the bottom