Is silicon a metal? No, silicon is classified as a metalloid because some of its properties resemble the properties of metals and some of its properties resemble those of nonmetals. The important properties of silicon and its classification on the periodic table are discussed in this article along with some of its key applications.
What are the Typical Properties of Metals and Nonmetals?
Typical Properties of Metals
The typical properties exhibited by almost all metals are listed below.
- Metallic lustre: most metals have a characteristic shiny appearance, especially when they are fractured or polished.
- Malleability: most metals have the ability to be beaten into very thin sheets. For example, aluminium can be beaten into a very thin foil. Gold is the most malleable metal, and it can be beaten into sheets whose thickness is in the order of nanometers.
- Ductility: Almost all metals can be drawn into wires. For example, copper is widely used in electrical wiring because it is a good conductor of electricity and is also highly ductile.
- Electrical conductivity: Metals are usually great conductors of electricity. This is because they are usually held together by metallic bonds, which contain a sea of delocalized electrons. Since electricity is nothing but the movement of electrons, the delocalized electron cloud that makes up metallic bonds attribute great electrical conductivity to metals.
- Thermal conductivity: Almost all metals have very high thermal conductivity. Furthermore, most metals have very high melting points as well. This enables metals to transfer large amounts of heat without melting.
Typical Properties of Nonmetals
The typical properties that are characteristic of most nonmetals are listed below.
- Low melting point: most nonmetals typically have very low melting points, especially when compared to those of metals.
- Low boiling point: most nonmetals usually have very low boiling points, especially when compared to the boiling points of metals.
- Density: most nonmetals typically have very low densities, especially when compared to the densities of metals.
- Poor electrical conductivity: almost all nonmetals are very poor conductors of electricity. In fact, most of them can be classified as insulators of electric currents.
- Poor thermal conductivity: most nonmetals are very poor conductors of heat and have very low thermal conductivity values. Furthermore, many nonmetals are known to melt very easily when heated.
- High ionization energy: usually, a large amount of energy must be supplied to a nonmetal in order to remove an electron from it.
- High electronegativity: nonmetals are known to be fairly electronegative. This makes them likely to form anions rather than cations. They typically gain or share electrons when they participate in chemical bonding.
- Brittleness: in their solid states, most nonmetals are very brittle. This implies that they easily crumble into a powder when some external pressure is applied on them.
What are Metalloids? Why is Silicon Classified as One?
Metalloids are chemical elements whose properties lie in between the typical properties of metals and nonmetals. The six elements that are widely known as the metalloids include silicon, germanium, antimony, arsenic, tellurium, and boron.
Typical Properties of Metalloids
The typical properties of metalloids are listed below.
- Metalloids usually have a shiny, metallic appearance.
- These elements are usually very brittle in nature and are known to easily crumble.
- They are not very good conductors of electricity. They can be considered as mediocre electrical conductors.
- Their chemical behaviour is similar to that of nonmetals.
Why is Silicon Classified as a Metalloid?
Silicon is classified as a metalloid since some of its properties are similar to those of metals and some of its properties are similar to those of nonmetals. For example, silicon is known to have a bluish-grey metallic lustre but is not an amazing conductor of electricity. This element is classified as a semiconductor.
Properties of Silicon
- Silicon is the chemical element that corresponds to the atomic number 14. This element is denoted by the symbol ‘Si’.
- It belongs to group 14 of the modern periodic table. It is a part of the carbon family.
- Silicon is known to be a p-block element. Its electronic configuration is given by [Ne]3s23p2. Since the valence electrons of this element fall under the 3p subshell, this element can be classified as a p-block element.
- Silicon has a total of four electrons in its outermost shell.
- Under standard conditions for temperature and pressure, silicon is known to exist in the solid phase.
- The melting point of silicon is approximately equal to 1687 Kelvin. Converting this Kelvin value into celsius, the melting point of silicon can be expressed as 1414 degrees celsius.
- The boiling point of silicon is approximately equal to 3538 Kelvin. Converting this Kelvin value into celsius, the boiling point of silicon can be expressed as 3265 degrees celsius.
- Under ambient conditions, the density of this element is roughly equal to 2.57 grams per cubic centimetre.
- Silicon has an electronegativity of 1.9 on the Pauling scale.
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