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Is silicon a metal? You might be confused by knowing that despite its metallic luster, which can make it look like a metal, we cannot classify silicon as a metal.
- It is classified as a metalloid, also known as semi-metal.
- You will get the properties of both metals and nonmetals in silicon.
- For example, it has a metallic luster (like a metal) but does not conduct electricity well, unlike a good metal.
- The conductivity of silicon increases with an increase in temperature i.e. opposite behavior for metals.
- Another interesting fact about silicon, you should know that silicon is the second most abundant element in Earth's crust, after oxygen.
In this article, we will learn about the properties of metals and nonmetals to understand why silicon, despite its metallic luster, is not classified as a metal.
| Table of Content |
Key Terms: Silicon, Metalloid, Metal, Nonmetal, Semi-metal, Chemical element, Electrical conductivity, Semiconductor
Properties of Metals
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Ever wonder what makes a metal a metal? Check out the table below to see some of the key properties that metals have.
| Properties of Metals | |
|---|---|
| Metallic luster | Metals have a metallic luster. They usually have a shiny appearance when they are being polished. |
| Ductility | It is the property of a metal to be stretched into thin wires without breaking. For example, copper is a highly ductile metal, which is why it is commonly used for electrical wires. |
| Electrical Conductivity | Metals are good electrical conductors because the electrons flow freely in them. |
| Thermal Conductivity | The thermal conductivity of all metals is very high. Furthermore, most metals have very high melting points as well. |
| Malleability | It is the property of any metal to form into thin sheets when hammered. For example, aluminum can be beaten into thin foil, gold can be flattened into sheets as thin as a few nanometers. |
Also check:
| Related Concepts | ||
|---|---|---|
| Periodic classification of elements | Classification of elements and periodicity | Classification of metals |
| Electromagnetic Waves MCQ | Electrochemistry | Refining of metals |
Properties of Nonmetals
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Now, after discussing the properties of metals, we will see the different properties of nonmetals so that we can differentiate between a metal and a nonmetal. The table given below gives us the different properties of Non-metal
| Properties of Nonmetals | |
|---|---|
| Brittleness | Most of the non-metals in their solid state are fragile or brittle. |
| Density | Most nonmetals have low density as compared to metals. |
| High ionization energy | A large amount of energy is required to remove an electron from nonmetals, therefore they have high ionization energy. |
| Low melting point | Nonmetals usually have a low melting point as compared to those of metals. |
| Low boiling point | Nonmetals usually have a low boiling point as compared to those of metals. |
| Poor electrical conductivity | Most nonmetals do not conduct electricity. Its conductivity lies between metals and nonmetals. |
| Poor thermal conductivity | Nonmetals have poor thermal conductivity. This means they heat up or cool down quickly. They also melt easily because they can not maintain their shape well when heated. |
| High electronegativity | Nonmetals have high electronegativity, meaning they have a strong tendency to attract electrons towards themselves when forming chemical bonds. |
What are Metalloids?
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If you look at the periodic table, you can observe that many different chemical elements are not categorized as metals or non-metals. We call these elements as Metalloids.
A metalloid is a chemical element that has the properties of both metals and non-metals. Six chemical elements are widely known as metalloids i.e. silicon, germanium, antimony, arsenic, tellurium, and boron.
Properties of Metalloids
The major properties of metalloids are given in the table below
| Properties of Metalloids | |
|---|---|
| Appearance | Metalloids have a metallic shiny appearance. |
| Brittleness | Just like nonmetals, metalloids are also brittle in nature. |
| Electrical Conductivity | They are poor conductors of electricity. They can be considered mediocre electrical conductors. |
| Chemical behavior | The chemical behavior of metalloids is similar to that of nonmetals. |
| Examples | Boron, Silicon, Germanium, Arsenic, Antimony, and Tellurium |
Why is Silicon Classified as a Metalloid?
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Silicon is categorized as a metalloid because it has characteristics comparable to both metals and nonmetals.
- For example, silicon has a bluish-grey metallic luster but is not a particularly good electrical conductor.
- We call this element a semiconductor.
Properties of Silicon
The following are the properties of silicon
| Property | Value |
|---|---|
| Atomic Number | 14 |
| Symbol | Si |
| Group | 14 (Carbon Family) |
| Block | p-block |
| Electron Configuration | [Ne]3s²3p² |
| Valance Electrons | 4 |
| State (at STP) | Solid |
| Melting Point | 1414 °C (1687 K) |
| Boiling Point | 3265 °C (3538 K) |
| Density | 2.57 g/cm³ |
| Electronegativity (Pauling scale) | 1.9 |
Also check:
| Related Concepts | ||
|---|---|---|
| Carbon and its compounds | Element | Metals and Non Metals Revision Notes |
| Electromagnetic Waves MCQ | Isotopes and isobars | Chemical Reactions and Equations |
Things to Remember
- Metalloids are the elements that have the properties of both metal and nonmetal.
- Silicon is a chemical element found in the 14th group of the scientific periodic table in chemistry.
- It is not a metal or nonmetal. It is a semimetal or Metalloid.
- The conductivity of silicon increases with an increase in temperature
- Six chemical elements are widely known as metalloids i.e. silicon, germanium, antimony, arsenic, tellurium, and boron.
Sample Questions
Ques. What is silicon in the periodic table? (2 Marks)
Ans. Silicon is a chemical element found in the 14th group of the scientific periodic table in chemistry. It is used for different purposes right from a small switchboard to smartphones to surgeries. The name Silicon derives from the Latin language term 'silex' or 'silicis'. The literal meaning of this word is 'hard stone'. Silicon was described as an element by Jöns Jacob Berzelius who was a Swedish chemist by profession.
Ques. Is silicon a metal, a nonmetal, or a metalloid? (2 Marks)
Ans. Silicon is not a metal or a nonmetal. Because silicon has the properties of both metals as well as nonmetals. It is known as metalloids or semi-metal.
Ques. Are silicon and silicone the same? (2 Marks)
Ans. Silicon and silicone are not the same. Silicon is the pure form of the metalloid but silicone is a mixture of oxygen, silicon, carbon, and hydrogen.
Ques. What is the atomic number of silicon? Also, show the symbol of silicon. (1 Mark)
Ans. The atomic number of silicon is 14. The symbol of silicon is Si.
Ques. Silicon belongs to which group of periodic tables? (1 Mark)
Ans. Silicon belongs to the P group of periodic tables.
Ques. Which silicon compound among these is used as an insulating material? (2 Marks)
(a) Silicon dioxide
(b) silicon carbide
(c) silicones
(d) zeolite
Ans. Option (c) silicones is the correct answer.
Explanation: Silicone is a mixture of oxygen hydrogen and silicon. It is different from Silicon because it is a mixture of other elements as well. Silicone is used as an insulating material in breast implants. Silicone rubber and silicone have insulating techniques within them. Silicone ensures heat and fire resistance.
Ques. When a mixture of silicon and coke is heated in an electric furnace, the product obtained is ________. (1 Mark)
Ans. Silicon Carbide
Ques. Which of the following statements is true about silicon? (2 Marks)
(a) As a metalloid, silicon is a good conductor of electricity like copper.
(b) As a metalloid, silicon sometimes behaves as a metal and sometimes as a non-metal.
(c) As a rare-Earth element, silicon is considered to be in short supply.
(d) As a semiconductor, the electrical properties of silicon cannot be changed.
Ans. Option (b) is correct.
Explanation: Among all the provided options, option b is correct. Silicon being a metalloid behaves like a metal sometimes and a nonmetal sometimes. It has a metallic appearance. But, it doesn't have good conductivity in terms of electricity.
Ques. Just like other metals, Silicon too has a metallic appearance. Then why is it not considered as a metal? (2 Marks)
Ans. It is true that Silicon has a metallic appearance but it is not considered a metal. This is because silicon is a metalloid having the properties of both metals as well as nonmetals. Silicon has a metallic appearance but its electric conductivity is not like that of metals. The boiling point of silicon is also low when compared to the metals. But still, Silicon has electrical conductivity and it has a metallic appearance. So it is not considered a nonmetal as well and it is categorized as a metalloid.
Ques. What are the physical properties of silicon? (3 Marks)
Ans. Below provided are the physical properties of silicon.
- At room temperature, Silicon exists as a solid.
- The atomic symbol of Silicon is Si.
- 14 is the atomic number of Silicon.
- The element category of Silicon is metalloid.
- Its density is 2.329 g/cm3.
- The melting point of Silicon is 2577°F and the boiling point is 5909°F.
- Moh's hardness of Silicon is 7.
- It exists as three natural isotopes.
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Found 5 Comments
Metals and Non-metals are the two major classifications of elements in the periodic table. Each of these elements possesses separate characteristics of its own. Metals are usually shiny, hard and good conductors of heat and electricity whereas non-metals are usually rough, non-malleable, non-ductile and poor conductors of electricity. Some examples of metals include sodium, iron, gold, silver, copper, etc. Examples of non-metals include gasses like chlorine, fluorine, sulphur, phosphorus, etc.
Pure silicon is a hard, dark gray solid with a metallic luster.
Covalent solids, like silicon, are brittle and hard compared to pure metals and ionic salts because dislocations do not migrate in them unless temperatures are very high.
Silicon has a shiny appearance, but it is brittle and has a poor electrical conductivity. Certain metalloids undergo characteristic changes in response to various elements.
Yes, Silicone is waterproof. Silicone caulks and sealants are extremely helpful for construction projects, particularly outside, because of their strong hold.
Metals are inorganic substances that form naturally with non-living things under the earth’s surface. It is hard and a good conductor of heat and electricity. Metals can be polished, drawn into wires and hammered into sheets. Names of a few metals are aluminium, copper and many more.
Silicon is the pure form of the metalloid but silicone is a mixture of oxygen, silicon, carbon, and hydrogen.