What do all of the objects pictured above have in common? All of them are made completely or primarily of copper. Copper has an amazing variety of uses, including cooking pots, plumbing pipes, roofing tiles, jewelry, musical instruments, and electric wires. Copper is a good choice for these and many other objects because of its properties. It can be formed into wires and flat sheets, it’s a great conductor of heat and electricity, it’s hard and strong, and it doesn’t corrode easily. In all these ways, copper is a typical transition metal.
What Are Transition Metals?
Transition metals are all the elements in groups 3–12 of the periodic table. In the periodic table pictured in Figure below, they are the elements shaded yellow, pink, and purple. The transition metals make up about 60 percent of all known elements. In addition to copper (Cu), well known examples of transition metals include iron (Fe), zinc (Zn), silver (Ag), and gold (Au) (Copper (Cu) is pictured in its various applications in the opening image). You can explore specific transition metals with the interactive periodic table at this URL: http://www.ptable.com/.
Q: Transition metals have been called the most typical of all metals. What do you think this means?
A: Unlike some other metals, transition metals have the properties that define the metals class. They are excellent conductors of electricity, for example, and they also have luster, malleability, and ductility. You can read more about these properties of transition metals below.
Properties of Transition Metals
Transition metals are superior conductors of heat as well as electricity. They are malleable, which means they can be shaped into sheets, and ductile, which means they can be shaped into wires. They have high melting and boiling points, and all are solids at room temperature, except for mercury (Hg), which is a liquid. Transition metals are also high in density and very hard. Most of them are white or silvery in color, and they are generally lustrous, or shiny. The compounds that transition metals form with other elements are often very colorful. You can see several examples in the Figure below.
Some properties of transition metals set them apart from other metals. Compared with the alkali metals in group 1 and the alkaline Earth metals in group 2, the transition metals are much less reactive. They don’t react quickly with water or oxygen, which explains why they resist corrosion.
Other properties of the transition metals are unique. They are the only elements that may use electrons in the next to highest—as well as the highest—energy level as valence electrons. Valence electrons are the electrons that form bonds with other elements in compounds and that generally determine the properties of elements. Transition metals are unusual in having very similar properties even with different numbers of valence electrons. The transition metals also include the only elements that produce a magnetic field. Three of them have this property: iron (Fe), cobalt (Co), and nickel (Ni).
Q: How is the number of valence electrons typically related to the properties of elements?
A: The number of valence electrons usually determines how reactive elements are as well as the ways in which they react with other elements.
Those Elements Down Under
Transition metals include the elements that are most often placed below the periodic table (the pink- and purple-shaded elements in the Figure above). Those that follow lanthanum (La) are called lanthanides. They are all relatively reactive for transition metals. Those that follow actinium (Ac) are called actinides. They are all radioactive. This means that they are unstable, so they decay into different, more stable elements. Many of the actinides do not occur in nature but are made in laboratories.
- Transition metals are all the elements in groups 3–12 of the periodic table. More than half of all elements are transition metals.
- Transition metals are typical metals, with properties such as a superior ability to conduct electricity and heat. They also have the metallic properties of luster, malleability, and ductility. In addition, transition metals have high melting and boiling points and high density.
- The lanthanides and actinides are the transition metals that are usually placed below the main part of the periodic table. Lanthanides are relatively reactive for transition metals, and actinides are radioactive.
At the following URL, click on any two of the transition metals and read about their properties, atomic structure, discovery, and uses. Then write a paragraph comparing and contrasting the two elements.
- What are transition metals?
- Describe properties of transition metals.
- How do transition metals differ from metals in groups 1 and 2? How are they different from all other elements?
- Identify the lanthanides and actinides.