Noble metals are a fascinating group of elements known for their remarkable properties, making them essential in various fields, from industry to jewelry making. But what are the noble metals? They’re definitely not the same thing as noble gases!
Today, let’s take a look at some shining examples of noble metals. We’ll go over what they are, their unique qualities, how they differ from noble gases, and where they can be found on the periodic table.
What Are Noble Metals?
Noble metals are a group of metallic elements known for their resistance to corrosion and oxidation in moist air, unlike most base metals.
This resistance to corrosion and oxidation is what makes them "noble," as they remain "noble" or pure even when exposed to harsh environmental conditions.
The term "noble metal" is often used to describe these metals because of their rarity and high economic value. However, this grouping doesn’t exactly have a strict definition, and there is some dispute over what is and what isn’t a noble metal– but we’ll go over that in a bit.
Properties and Qualities of Noble Metals
Noble metals share several key properties that set them apart from other elements.
Resistance to Corrosion
One of the most defining characteristics of noble metals is their ability to resist corrosion. Unlike metals like iron, which rusts when exposed to moisture and oxygen, noble metals maintain their luster and structural integrity over time.
High Density and Malleability
Many noble metals, such as gold and platinum, are highly dense and malleable. This makes them ideal for various applications, including jewelry and industrial uses where precision and durability are required.
Conductivity
Noble metals are excellent conductors of electricity and heat. This makes them invaluable in electronic applications, where reliable conductivity is crucial.
Catalytic Properties
Some noble metals, particularly platinum and palladium, are used as catalysts in chemical reactions. Their ability to speed up reactions without being consumed makes them essential in industries like automotive manufacturing, where they are used in catalytic converters.
Found Raw
This characteristic is where the noble metals get a little confusing. Most of the elements considered noble metals are found in their raw form in nature– but silver, copper, and mercury, which are often included as noble metals, usually occur in nature combined with sulfur.
Regardless, all noble metals require fairly intense mining operations to extract them from their ores, since they are relatively rare and often found in remote locations.
Noble Metals vs. Noble Gases
Noble metals and noble gases are often confused due to their similar names, but they are entirely different groups of elements with distinct properties. As mentioned, noble metals are known for their resistance to corrosion and are found in the d-block of the periodic table. They are solid at room temperature and have high density, malleability, and conductivity.
However, noble gases are called “noble” for a very different reason. While noble metals are prized for their durability and conductivity, noble gases are valued for their inertness and stability in chemical reactions. And while the noble metals are not strictly defined, noble gases are.
The noble gases are Group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Each is a colorless, odorless, and tasteless gas under standard conditions, and they fluoresce, or glow, in the presence of an electric field.
Where Are Noble Metals Found on the Periodic Table?
Noble metals are primarily located in the d-block of the periodic table, also known as the transition metals. This area includes elements with partially filled d orbitals, which gives them unique chemical properties.
The group of noble metals known as the platinum group metals (the group that includes elements such as gold, platinum, and palladium) are found in Groups 8 through 11. These metals are characterized by their resistance to corrosion and oxidation, making them less reactive than other elements.
The main group of noble metals are situated near other precious and valuable metals, like silver and copper, which share similar properties and are sometimes included in the noble metals classification.
The noble metals are clustered in the lower right section of the transition metals, highlighting their shared traits of high density, malleability, and excellent conductivity, which contribute to their widespread use in jewelry, electronics, and industrial applications.
Noble Metals List
Generally, the elements considered noble metals are the platinum group metals:
- Gold (Au), Atomic Number 79
- Platinum (Pt), Atomic Number 78
- Palladium (Pd), Atomic Number 46
- Rhodium (Rh), Atomic Number 45
- Ruthenium (Ru), Atomic Number 44
- Iridium (Ir), Atomic Number 77
- Osmium (Os), Atomic Number 76
And some scientists extend this list to include:
What Are Noble Metals Used For?
Noble metals have a wide range of applications due to their unique properties. They have lots of common uses and more obscure scientific and industrial uses.
- Gold: jewelry, electronics, currency
- Platinum: catalytic converters, jewelry, medical devices, surgical tools
- Palladium: catalytic converters, electronics, jewelry, electron microscopy
- Rhodium: catalytic converters, plating, electrical contacts
- Ruthenium: electrical contacts, alloys, catalysts
- Iridium: spark plugs, electrodes, alloys
- Osmium: alloys, fountain pen nibs, electrical contacts
- Silver: jewelry, electronics, photography, currency
- Copper: electrical wiring, plumbing, coins
- Mercury: thermometers, barometers, dental amalgams
The Importance of Noble Metals
Noble metals play an essential role in various industries, from electronics and jewelry to automotive and medical applications. Their unique properties, such as resistance to corrosion, high conductivity, and catalytic abilities, make them invaluable.
Understanding noble metals and their applications provides insight into why these elements have been prized for centuries and continue to be crucial in modern technology.
As you explore the world of noble metals, you'll discover their impact on everything from the devices we use daily to the air we breathe, thanks to their role in reducing emissions. Whether you're an industry professional or simply curious about these remarkable elements, noble metals are truly worth their weight in gold.
If you want to get up close and personal with the noble metals, Engineered Labs can help you out. These elements are extremely important for students of chemistry, electrical engineering, materials science, geology, and numerous other fields of study– so having a classroom example on hand makes them easy to teach.
Check out our selection of acrylic element cubes to see these elements for yourself!
