Alkali Metals: Properties and Reactions
This page provides an overview of the alkali metals and their chemical properties, focusing on their reactivity with water and the trends observed within Group 1 of the periodic table.
The alkali metals are described as highly reactive elements, with their reactivity increasing as you move down the group. This trend is attributed to the increasing atomic size, which makes it easier for the outermost electron to be lost during chemical reactions.
Vocabulary: Alkali metals are the elements in Group 1 of the periodic table, including lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
The page illustrates the reaction of alkali metals with water, providing chemical equations for lithium, sodium, and potassium:
Example:
Lithium: 2Li + 2H₂O → 2LiOH + H₂
Sodium: 2Na + 2H₂O → 2NaOH + H₂
Potassium: 2K + 2H₂O → 2KOH + H₂
These reactions demonstrate that when alkali metals react with water, they produce a metal hydroxide and hydrogen gas.
Highlight: The reactivity of alkali metals increases down the group due to the increasing atomic size, which makes it easier for the outer electron to be lost.
The page also mentions some physical properties of alkali metals, noting that they have low density. This property, combined with their high reactivity, contributes to their unique behavior in chemical reactions.
Definition: Reactivity in chemistry refers to the tendency of an element to undergo chemical reactions. For alkali metals, their high reactivity is due to their electronic configuration, with one easily lost electron in the outermost shell.
Understanding the properties and reactions of alkali metals is crucial in chemistry, as it helps explain many phenomena and has practical applications in various fields.
