Alkali metals and alkaline earth metals are both groups of elements found in the periodic table, but they have distinct differences in their properties and behaviors.
**Alkali Metals:**
1. **Group:** Alkali metals are found in Group 1 of the periodic table.
2. **Electron Configuration:** They have one electron in their outermost shell.
3. **Reactivity:** These metals are highly reactive, especially with water, and they tend to form strong bases when they react with water.
4. **Examples:** Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
5. **Physical Properties:** They are soft metals with low melting points and densities.
**Alkaline Earth Metals:**
1. **Group:** Alkaline earth metals are found in Group 2 of the periodic table.
2. **Electron Configuration:** They have two electrons in their outermost shell.
3. **Reactivity:** These metals are less reactive compared to alkali metals, but they still react with water and oxygen, though not as vigorously.
4. **Examples:** Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).
5. **Physical Properties:** They are harder and have higher melting points and densities compared to alkali metals.
In summary, the main differences between alkali metals and alkaline earth metals lie in their group placement, electron configuration, reactivity, and physical properties. Alkali metals are more reactive and have one valence electron, while alkaline earth metals are less reactive and have two valence electrons.