* Francium (Fr) is an alkali metal. Alkali metals are known for their low melting and boiling points. This is because their metallic bonds are weak due to their single outer electron. Francium's melting point is a mere 27°C (81°F), making it a liquid at room temperature.
* Platinum (Pt) is a transition metal. Transition metals generally have much higher melting points than alkali metals. Platinum's melting point is incredibly high at 1768°C (3214°F). This is due to the strong metallic bonds formed by their multiple valence electrons.
In summary: Francium, being an alkali metal, has a very low melting point compared to the transition metal platinum.
