Here's why:
* Alkali metals (Group 1 on the periodic table: lithium, sodium, potassium, rubidium, cesium, and francium) are highly reactive.
* They have a single valence electron, making them eager to lose it and form a +1 cation.
* This reactivity is amplified by their low ionization energies, meaning it takes very little energy to remove that single electron.
When alkali metals react with water, they donate their electron to a hydrogen atom in the water molecule, forming hydrogen gas (H₂) and a metal hydroxide.
Example:
* Sodium reacting with water:
2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)
The reaction is exothermic, meaning it releases heat, and in the case of sodium, the hydrogen gas can ignite.
Important Note: This reaction is highly dangerous and should only be performed by experienced professionals in a controlled laboratory setting.
