* Alkali metals: These are found in Group 1 (IA), the first column on the left side of the periodic table. They include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
* Alkaline earth metals: These are found in Group 2 (IIA), the second column on the left side of the periodic table. They include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
Why are these elements base-forming?
* Electronic configuration: Both alkali and alkaline earth metals have only one or two valence electrons, respectively, in their outermost electron shell. These electrons are easily lost, forming positively charged ions (cations).
* Reaction with water: When these metals react with water, they release hydrogen ions (H+) and form hydroxide ions (OH-) in solution. This makes the solution alkaline or basic.
For example:
* Sodium (Na) reacts with water to form sodium hydroxide (NaOH), a strong base:
* 2Na + 2H₂O → 2NaOH + H₂
* Calcium (Ca) reacts with water to form calcium hydroxide (Ca(OH)₂), a strong base:
* Ca + 2H₂O → Ca(OH)₂ + H₂
It's important to note that not all elements in these groups form bases. For example, beryllium (Be) is amphoteric, meaning it can act as both an acid and a base.
