Position of some special elements in periodic table

Position of Alkali Metals, Alkaline Earth Metals, Halogens, and Inert Gases in the Periodic Table

The modern periodic table is arranged in horizontal rows known as periods and vertical columns referred to as groups. Elements are arranged based on increasing atomic number, and their properties show periodic trends. Certain groups contain elements with very distinct and important characteristics. Among these are alkali metals, alkaline earth metals, halogens, and inert gases (noble gases).

1. Alkali Metals (Group 1)

Elements classified as alkali metals are found in Group 1 of the periodic table. This group includes Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).

Key Characteristics:

• Highly reactive, especially with water
• Have one valence electron
• Form strong bases called alkalis
• Stored under oil to prevent reaction with air

2. Alkaline Earth Metals (Group 2)

These elements are found in **Group 2** and include Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).

Key Characteristics:

• Less reactive than alkali metals, but still reactive
• Have two valence electrons
• Form alkaline solutions when reacted with water
• Commonly occur in nature in the form of chemical compounds within the Earth's crust

3. Halogens (Group 17)

Halogens belong to Group 17 of the periodic table. This group includes elements such as Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At).

Key Characteristics:

• Very reactive non-metals
• Have seven valence electrons
• Readily form salts with metals (e.g., NaCl)
• Exist in various physical states: gas (F₂, Cl₂), liquid (Br₂), solid (I₂)

4. Inert Gases / Noble Gases (Group 18)

Noble gases are positioned in Group 18 of the periodic table. This group consists of elements such as Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).

Key Characteristics:

• Extremely unreactive due to fully filled outer electron shells
• Present as single-atom gases under standard conditions
• Utilized in applications like lighting, welding, and providing non-reactive settings for chemical processes
• Helium is also used in weather balloons due to its low density

Understanding the position of these element groups in the periodic table helps explain their chemical behavior and importance. From reactive alkali metals to unreactive noble gases, each group plays a crucial role in the chemical world.