Noble Gases: Understanding Group 18 Elements
Discover the fascinating world of noble gases, their unique properties, and why they don't conduct electricity. Learn about their applications in industry and science, from lighting to medical imaging.

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Now Playing:Group 18 noble gases – Example 0a
Intros
  1. Noble gases: A summary
  2. History of the noble gases.
  3. Properties of the noble gases.
Examples
  1. Apply your knowledge of types of bonding to explain the properties of the noble gases.
    Explain why the noble gases have such a low melting and boiling point compared to other groups in the Periodic Table.
    Introduction to chemical reactions
    Notes
    In this lesson, we will learn:
    • To recall the properties of noble gases.
    • To understand some of the uses of the noble gases.
    • To apply understanding of electronic structure to explain the properties of the noble gases.

    Notes:

    • We have seen that the Periodic Table is arranged, top-left to bottom-right, by proton number and number of outer shell electrons. The number of outer shell electrons dictates the chemical properties of an element.
      Therefore, you can see which elements have similar properties – they will be in the same column of the table as each other - the columns which we call groups.

    • The noble gases are another group of well-studied elements in the periodic table with a specific set of properties that make them unique. They are in group 8 (18 if you include transition metals), the right-most column of the table.

    • The noble gases have the following properties:
      • They are colorless, odorless gases.
      • They are very unreactive – this is the most important fact to know about noble gases. It is the main reason the whole group of noble gases were discovered very late (after Mendeleev had developed the Periodic Table). Being gases with no color or smell humans could sense, and no reactions with anything around them to study, chemists could not prove they were there!
      • Noble gases exist as single, monatomic atoms.
      • They are non-metals and are therefore very poor conductors of electricity.

    • There is not much change in the properties of noble gases going down the group, however their melting and boiling point does slightly increase – however all of them are still well below zero degrees Celsius. The density of the noble gases also increases going down the group.

    • Despite their unreactive nature they have a few important uses:
      • Helium is used in hot air balloons and air ships. Objects filled with helium float because helium isn't as dense as air. It is also used in air containers for deep sea divers. At high underwater pressure, too much nitrogen and oxygen gets into the blood causing toxic side effects. Because it is inert, if some air in the containers is replaced by helium, it keeps the container pressurized, and the helium has no side effects on the divers because it is inert!
      • Neon is used in signs – if an electric current is ran through a glass tube with neon in it, the gas will start glowing.
      • Argon is used in small quantities to protect light bulb filaments – the very hot filament metal burns in oxygen but not in argon.
    Concept

    Introduction to Noble Gases

    Noble gases, also known as inert gases, occupy the rightmost column of the periodic table. This unique group of elements, including helium, neon, argon, krypton, xenon, and radon, was the last to be discovered, making them a fascinating subject in chemistry. These elements are characterized by their full outer shell of electrons, which contributes to their remarkable stability and low reactivity. The introduction video provided offers an essential overview of noble gases, their properties, and their significance in various applications. Understanding noble gases is crucial for grasping fundamental concepts in chemistry and physics. Their discovery revolutionized our understanding of atomic structure and chemical bonding. Despite their name suggesting inertness, noble gases can form compounds under specific conditions, leading to exciting research opportunities. Their unique properties, such as low boiling points and high ionization energies, make them valuable in numerous industrial and scientific applications, from lighting to medical imaging.

    FAQs

    Here are some frequently asked questions about noble gases:

    1. What is the noble gases group number?

    Noble gases are in Group 18 of the periodic table. This group was formerly known as Group 0 or Group VIIIA in older periodic table notations.

    2. Do noble gases conduct electricity?

    Under normal conditions, noble gases do not conduct electricity. They are excellent insulators due to their stable electron configuration. However, they can become conductive when ionized under specific conditions, such as in neon signs.

    3. Why is neon used in lighting?

    Neon is used in lighting because it produces a bright orange-red glow when an electric current passes through it. This property makes it ideal for signs and decorative lighting. Other colors can be achieved by using different gases or phosphor coatings.

    4. Why is argon used in light bulbs?

    Argon is used in incandescent light bulbs because it's inert and doesn't react with the hot tungsten filament. It also has low thermal conductivity, which helps maintain the filament's high temperature, improving efficiency and bulb lifespan.

    5. Can noble gases form compounds?

    While noble gases are generally unreactive, some can form compounds under specific conditions. Xenon, for example, can form compounds with highly electronegative elements like fluorine. These compounds are rare and typically require extreme conditions to form.

    Prerequisites

    Understanding Group 18: Noble gases requires a solid foundation in key chemistry concepts. Two crucial prerequisite topics are atomic structure and the history and development of the periodic table. These fundamental areas of study provide the necessary context and knowledge to fully grasp the unique properties and behaviors of noble gases.

    A thorough understanding of atomic structure is essential when studying noble gases. This topic covers the basic components of atoms, including protons, neutrons, and electrons, as well as their arrangement within the atom. Noble gases are characterized by their full outer electron shells, which directly relates to their atomic structure. By comprehending how electrons are distributed in energy levels and orbitals, students can better appreciate why noble gases are so chemically inert and stable.

    The history and development of the periodic table is another critical prerequisite for understanding noble gases. This topic explores how scientists organized elements based on their properties and atomic structure. Noble gases play a significant role in this history, as their discovery and placement in the periodic table helped complete and validate the table's structure. Learning about the periodic table's evolution provides insight into why noble gases form their own distinct group and how their properties relate to their position in the table.

    By mastering these prerequisite topics, students will be better equipped to explore the fascinating world of noble gases. The atomic structure knowledge will help explain why noble gases have full outer electron shells and how this influences their chemical behavior. Meanwhile, understanding the periodic table's development will provide context for the noble gases' discovery and their importance in completing the table's arrangement.

    As students delve into Group 18: Noble gases, they'll find that their prior knowledge of atomic structure helps them comprehend why these elements are so unreactive and have such high ionization energies. Similarly, their familiarity with the periodic table's history will enhance their appreciation of how noble gases fit into the broader picture of element classification and chemical trends.

    In conclusion, a solid grasp of atomic structure and the history of the periodic table serves as a crucial foundation for studying noble gases. These prerequisite topics provide the necessary context and fundamental principles that make the study of Group 18 elements more accessible and meaningful. By investing time in these foundational concepts, students will be well-prepared to explore the unique properties and applications of noble gases in greater depth.