Our world is made primarily of metal. You encounter metals every single day, and chances are, the majority of the ones you encounter fall into the third category on the periodic table — the transition metals. What are transition metals, and where might you encounter them in your daily life?
Properties of the Transition Metals
First, what are transition metals? There are a lot of elements in this section. Transition metals consist of groups 3 through 12 on the periodic table. This makes of 38 elements in total. We’ll go more into each element in detail in a moment. The transition metals include:
These metals are considered the transition or bridge between the main group elements on either side of the table. They create a bridge between the alkali metals and alkaline earth metals on the left side of the table, known as active metals, and the metals, semimetals and nonmetals on the right-hand side of the table.
These metals earned their moniker in 1921 when they were dubbed the transition series of elements by an English chemist named Charles Bury.
The International Union of Pure and Applied Chemistry (IUPAC) defines these transition metals as “any element with a partially filled d-electron sub-shell.” Elements are divided into and defined by one of four different electron orbitals – designated s, p, d and f – and the latter three also have sub-levels or sub-shells that can hold even more electrons. The orbital designation helps chemists determine where each element falls on the periodic table.
As you move across the periodic table from left to right, these sub-shells become progressively more filled.
One unique property of these transition metals is the fact that they’re essential for biological life to function. Many of them, from iron and cobalt to copper and things like molybdenum are necessary to keep us alive and healthy. Without enough iron in your bloodstream, your body can’t property transport oxygen through your body. Other transition metals, like copper and cobalt, exist as trace elements in your body, and the full extent of their applications isn’t entirely understood.
There are two other categories — lanthanides and actinides — which reside on the bottom part of the periodic table. People sometimes refer to them as the inner transition metals since their atomic numbers fall between the first and second elements on the last two rows of transition metals. However, we’ll get into those at a later date.
Chemical and Physical Traits
All these elements are metals, meaning they’re shiny in appearance, exhibiting the telltale metallic luster that defines them as metals. Most of them are very hard, have high melting points and boiling points so high it’s nearly impossible to reach them. Almost all of them are good at conducting both heat and electricity, making them useful for a variety of applications.
The most common use for the metals in periods 4, 5 and 6 is in alloys, which makes them incredibly versatile. Alloys are mixtures of two or more metals to make the finished product stronger, lighter or easier to work with.
They’re usually incredibly malleable, though some require very high temperatures to make them malleable enough to work with. Many of these metals, such as iron and copper, also have useful structural properties. They are able to bend and be reshaped without losing their structural integrity and strength. While you can take a piece of iron or copper and bend it back and forth over and over to weaken its bonds or cause it to break, under most applications, these metals retain their structural integrity regardless of their shape.
These metals, on the atomic level, tend to lose electrons when bonding. This causes them to create positive ions. These metals also often form colored complexes, which means that if you find them in different compounds or solutions, they might be very colorful. A few examples of this include malachite which is a bright green, azurite which usually appears as a brilliant blue, and proustite, which is a deep red.
Some of the metals in this category are reactive, but they don’t react nearly as quickly or as violently as those in the alkali metals category. Their partially filled electron sub-shells also mean these metals can exhibit multiple different oxidation states, usually separated by a single electron. These varying oxidation states make most transition metals paramagnetic as well — they demonstrate weak magnetic attraction but won’t retain any sort of permanent magnetism. We say most, because there are at least three metals in this category that are considered ferrous, so they are magnetic and react strongly to magnetic fields.
Transition metals also demonstrate high catalytic activity. In other words, the elements in this section, as well as their compounds, act as good catalysts. They will either react with something, changing their oxidation state in the process, or they will absorb substances that sit on their surface, activating them. Catalysts work by creating catalytic pathways for a reaction to follow. These metals are more than happy to take on new electrons or donate the ones they already have to fuel these reactions.
Many of the transition metals are among the most abundant elements on Earth. Iron is the fourth most abundant. Titanium comes in 10th and manganese comes in 13th. Other transitional metals, like gold and silver, are also abundant, but they don’t rank nearly as high as those previously mentioned.
There are no official families for the members of the transition metals, but people often give them unofficial designations, especially for the most commonly used ones. Let’s take a look at the most common designations for transition metal groups and where you might encounter them in real life.
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It can be hard to break down some of these elements because not all of them have common applications, so let’s take a look at some of the unofficial group designations for commonly used transition metals.
Ferrous or Magnetic Metals
Ferrous metals are those that react with a magnetic field — it’s why you can stick a magnet to a steel refrigerator but not an aluminum car bumper. These metals include:
- Iron: We came up with so many uses for iron over the centuries that it would take us an entire piece just to list them all. It comes in a variety of forms, such as pig iron that’s smelted in a coke-burning furnace, cast iron that mixes iron with silicon or carbon, wrought iron and steel. Steel is just iron mixed with two other transition metals, manganese and chromium, and purified at high temperatures. You also find iron in your blood, in the form of hemoglobin.
- Cobalt: We discovered cobalt in 1735 and named it for the word kobald. Kobald comes from German folklore and refers to an underground gnome. This metal got its name because it was so difficult to mine. The ore itself also contains arsenic, which both gives the ore its brilliant blue color and makes it toxic to handle. It was used in blue paint in the past, and today it’s primarily used as part of a magnetic alloy that also includes iron, nickel and aluminum. It is also used in engines and jet turbines.
- Nickel: It’s not in nickels anymore, but this element makes up a number of other items. This is another metal that used to give miners fits — it looked like copper but wasn’t, earning it the nickname Kupfernickel — German for imp copper. Today, nickel is an anti-corrosive additive, or coating, for other metals.
As the name suggests, people either used these metals in coins in the past or still use them in currency today.
- Gold: Do we really need to describe gold? It’s been in coins and jewelry for centuries. Gold is soft, malleable, can easily shaped into just about anything. One troy ounce hammered into a sheet stretches over 68 square feet. It’s either been used as direct currency or to support currency for centuries. The United States used the gold standard to support its currency until the 1930s, and still maintains massive stores of gold bullion.
- Silver: Often considered less valuable than gold, silver is nonetheless more useful. It’s harder than gold, but once molten it casts into nearly any shape. This is useful for things like dishes and silverware. Where do you think silverware got its name? You won’t find silver in currency anymore, but it’s great for making jewelry, developing photos, and many electronics applications.
- Copper: Most people think of pennies when they think of copper, but U.S. pennies actually have no copper content in them at all anymore, other than a very thin copper coating. You can find copper in bronze because it’s an essential component for making the alloy. The most commonly use for copper today is in electrical applications due to its fantastic conductivity. Thick copper plates cover America’s most famous landmarks as well. The oxidation of the copper gives her the iconic green coloring.
Alloy metals are essential to most modern construction, simply because of their abundance and the frequency with which they are used. Eleven of them make up this group because they are frequently found together in nature. Let’s take a brief look at these metals.
- Titanium: This extremely high-strength metal is used in a lot of modern construction. People discovered it in the late 1700s but only isolated it in 1910. They named the element after the Titans of Greek mythology because of its monumental strength. Today, we use it for everything from making cars and buildings to airplanes and spacecraft, because it is so light and inherently resistant to corrosion.
- Zirconium: Scientists identified Zirconium around the same time as titanium, but again, they didn’t isolate it until the early 1900s. Scientists discovered Zirconium inside the mineral zircon, which is where it gets its name. Today, zirconium helps create superconducting magnets and furnace linings. You may even find it in poison ivy lotion at your local pharmacy.
- Hafnium: You may encounter this element in lightbulb filaments, but it may not be hafnium at all. Scientists almost always discover it with zirconium and the two elements are so hard to separate you might end up with the wrong one.
The rest of the alloy metals don’t have a ton of applications, but we’ve listed a few for you. You probably won’t encounter the rest of these in your everyday life.
- Chromium — used to chrome-treat metals and used in stained glass.
- Vanadium — used as a bonding agent when alloying steel and titanium.
- Tantalum — used in alloys for its high melting point.
- Niobium — almost always found with tantalum, difficult to separate the two.
- Molybdenum — used in alloys with tungsten for metal strengthening.
- Tungsten — has the highest melting point of any metal, used in alloys to raise metal melting points.
- Manganese — used to increase metal strength during steelmaking.
- Rhenium — used in alloys with tungsten for metal strengthening.
If you’ve handled something made of tungsten, chances are you’ve encountered most of the alloy metals in one piece. However, without breaking it down into its component parts, it’s impossible to tell.
The Zinc Family
People call the members of this group “the zinc family” because they occupy the same group on the periodic table. They do tend to demonstrate very different properties, though.
- Zinc: Zinc, when alloyed with copper, creates brass — which is another metal like bronze that helped shape the modern world. We’ve used brass to make everything from weapons and armor to coins and jewelry over the years. Today, zinc has a variety of different applications, including making lightbulbs, movie screens, fabrics, batteries, paints and anti-corrosive coatings for other metals.
- Cadmium: Cadmium is useful in electroplating, a process that protects other metals from corrosion, similar to zinc. It is also essential to the everyday operations of nuclear power plants because it is used in the control rods. It’s difficult to separate cadmium from zinc though, which makes it very expensive. You don’t want to mess around with cadmium anyway — it’s very toxic!
- Mercury: If you thought cadmium was toxic, just wait until we get to mercury. This is the only metal that naturally exists in a liquid state. Its melting point is -37 degrees F, so it is almost always in liquid form. Back in the day it filled thermometers because it expands evenly when heated. When super-cooled to near absolute zero, it also presents some superconducting properties.
The Platinum Group
People refer to the next group of metals as the platinum group because they tend to appear together in nature. Not all of these metals have common applications, though.
- Platinum: Platinum, now considered a precious metal, used to be a nuisance. It got in the way when miners were looking for gold, tended to be hard to mine and didn’t have a ton of applications back in the day. It’s almost always found with the other minerals in the platinum group, and can be difficult to separate them. Today, you’ll find it in jewelry, thermometers, catalytic converters on cars and even in rocket engines because of its high melting point.
- Iridium: This element gets its name from its multicolored hue. Iridium is primarily use is for the creation of laser crystals that have to withstand high temperatures.
- Osmium: Almost always discovered with iridium, osmium is useful in electrical applications and in the creation of fountain pens.
- Palladium: Palladium helps those extracting hydrogen because it can absorb up to 900 times its volume in the element.
- Rhodium: Named for its red color, this element hardens platinum.
- Ruthenium: No known applications.
Honorable Mentions or Elements You Don’t Want to Encounter
You’ve probably noticed there are still a few elements we haven’t mentioned from the ones listed above. These elements have no application in everyday life, and hopefully, you’ll never encounter them.
Scientists discovered scandium and yttrium in Scandinavia. Scandium has no known applications, and yttrium’s useful in alloys to add strength to other metals.
The rest of the transition metals don’t occur naturally. Other than technetium, created in a lab in 1936, all these elements have atomic numbers higher than that of uranium, earning them the name transuranium elements. You don’t want to encounter any of these elements — they’re all highly radioactive. Chances are you won’t, though — scientists can only create them in the lab, and once created, they only last a few 188博金宝电子游戏 before they deteriorate.
Transition metals make up the whole middle part of the periodic table, and with 38 elements to choose from, you’ll probably encounter at least one of them in your everyday life. If you’re reading this on a phone, you’ve got copper, silver and possibly platinum right in your hand. Where have you encountered transition metals in your daily life?