Alkaline Metals and Alkaline Earth Metals: A Simple Guide

Alkaline Metals and Alkaline Earth Metals are two groups found in the periodic table. They have different properties and characteristics.

1. Where They Are in the Periodic Table:

• Alkaline Metals (Group 1): These are found in the first column. The elements in this group are:

  • Lithium (Li)
  • Sodium (Na)
  • Potassium (K)
  • Rubidium (Rb)
  • Cesium (Cs)
  • Francium (Fr)

• Alkaline Earth Metals (Group 2): These elements are in the second column. They include:

  • Beryllium (Be)
  • Magnesium (Mg)
  • Calcium (Ca)
  • Strontium (Sr)
  • Barium (Ba)
  • Radium (Ra)

2. Reactivity:

• Alkaline Metals: These metals are very reactive. They have one electron in their outer shell. The reactivity increases as you go down the group. For example, Francium is the most reactive and can react with water in a very explosive way.

• Alkaline Earth Metals: These metals are not as reactive as alkaline metals. They have two outer electrons. They do react with water but not as quickly. Calcium and Magnesium can react with water, but Barium does so more energetically.

3. Physical Properties:

• Density: Alkaline metals are lighter. For example:

  • Lithium has a density of 0.53 g/cm³.
  • Francium has a density of 1.87 g/cm³.

  In contrast, Magnesium has a density of 1.74 g/cm³.

• Melting Points: Alkaline metals have lower melting points. For instance, Sodium melts at 98 °C, while Magnesium melts at a much higher 650 °C.

4. Compounds:

• Alkaline Metals: These metals form strong compounds, like sodium hydroxide (NaOH).

• Alkaline Earth Metals: They form compounds that are not as easily dissolved, like calcium hydroxide (Ca(OH)₂).

In Summary:

Both groups have some similarities, but they differ a lot in how they react, their physical properties, and how they behave chemically.