The Periodic Table: Noble Gases

The Periodic Table: Noble Gases

The Noble Gases

• The noble gases are located in Group 0 of the Periodic Table.
• They include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
• They are all monatomic gases, which means they exist as single atoms instead of diatomic (two-atom) molecules like many other gases.

Properties

• Noble gases are unreactive. This is due to their stable electron configuration, with a full outer shell.
• They have low boiling and melting points, which increase down the group.
• These gases are colourless and odourless, and conduct electricity poorly.

Uses

• Helium is used in party balloons and blimps because it is lighter than air.
• Neon is used in advertising signs due to its ability to glow brightly when electrified.
• Xenon and krypton are often used in high intensity lighting, like car headlights and cinema projectors.

Patterns and Trends

• As you move down the group, atomic size and atomic mass increase.
• Noble gases have the highest ionisation energies in their respective periods.

Hazards and Handling

• Noble gases are generally safe to handle due to their low reactivity.
• However, radon is radioactive and can be harmful if inhaled; it is a known carcinogen.
• Extra care should be taken while handling pressurised containers of these gases.

Significance of Noble Gases

• Discovery of noble gases challenged the periodic law at the time of their discovery as they did not fit the existing pattern.
• However, this led to a better understanding and refinement of the Periodic Table.
• They have also given insight into other phenomena, such as valence and chemical bonding.