Alkali metals are a special group of elements found in Group 1 of the Periodic Table. They have some interesting properties that set them apart from other elements. Let’s take a closer look!

1. Reactivity:

• Alkali metals are very reactive.
• This means they easily combine with other things.
• As you go down the group, they become even more reactive.
• For example, lithium (Li) reacts slowly with water, but cesium (Cs) reacts with a big explosion!

2. Atomic Structure:

• All alkali metals have one electron in their outer shell.
• They easily lose this electron to become +1 ions.
• This is why they have low ionization energies.
• Here’s how it works for a few of them:
  • Lithium (Li): 520 kJ/mol
  • Cesium (Cs): 376 kJ/mol
  • Francium (Fr) is estimated to be around 390 kJ/mol.

3. Physical Properties:

• Alkali metals are usually soft, and you can cut them with a knife.
• They also have low densities, which means they are light.
• Lithium, sodium (Na), and potassium (K) can even float on water!
• Their melting points get lower as you go down the group, like this:
  • Lithium (Li): 180.5 °C
  • Cesium (Cs): 28.5 °C.

4. Compounds:

• Alkali metals like to form ionic compounds.
• A common example is sodium chloride (NaCl), which is table salt.
• These compounds can easily dissolve in water.

These unique features show why alkali metals in Group 1 are so interesting!