metals

what are metals

Metals are elements that can conduct electricity. They are one of three classes of elements (the other two classes are nonmetals and metalloids). Metals are by far the largest of the three classes. In fact, most elements are metals. All of the elements on the left side and in the middle of the periodic table, except for hydrogen, are metals. There are several different types of metals, including alkali metals in group 1 of the periodic table, alkaline Earth metals in group 2, and transition metals in groups 3-12. The majority of metals are transition metals.

properties of metals

Elements in the same class share certain basic similarities. In addition to conducting electricity, many metals have several other shared properties, including those listed below. Metals have relatively high melting points. This explains why all metals except for mercury are solids at room temperature. Most metals are good conductors of heat. Thats why metals such as iron, copper, and aluminum are used for pots and pans. Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury pictured above is very shiny. The majority of metals are ductile. This means that they can be pulled into long, thin shapes, like the aluminum electric wires pictured in the Figure 1.1. Metals tend to be malleable. This means that they can be formed into thin sheets without breaking. An example is aluminum foil, also pictured in the Figure 1.1. Q: The defining characteristic of metals is their ability to conduct electricity. Why do you think metals have this property? A: The properties of metalsas well as of elements in the other classesdepend mainly on the number and arrangement of their electrons.

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explaining the properties of metals

To understand why metals can conduct electricity, consider the metal lithium as an example. An atom of lithium is modeled below. Look at lithiums electrons. There are two electrons at the first energy level. This energy level can hold only two electrons, so it is full in lithium. The second energy level is another story. It can hold a maximum of eight electrons, but in lithium it has just one. A full outer energy level is the most stable arrangement of electrons. Lithium would need to gain seven electrons to fill its outer energy level and make it stable. Its far easier for lithium to give up its one electron in energy level 2, leaving it with a full outer energy level (now level 1). Electricity is a flow of electrons. Because lithium (like most other metals) easily gives up its extra electron, it is a good conductor of electricity. This tendency to give up electrons also explains other properties of metals such as lithium.

instructional diagrams

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questions

metals are the largest of the three classes of elements.

-->  a. true

b. false

properties of most metals include

a) high melting point.

b) ability to conduct heat.

c) shiny appearance.

-->  d) all of the above

some metals are gases at room temperature.

a. true

-->  b. false

the properties of metals depend mainly on their number and arrangement of neutrons.

a. true

-->  b. false

diagram questions

No diagram questions associated with this lesson