Math Is Fun Forum

Metalloid

Gist

A metalloid is a chemical element that has properties intermediate between those of metals and nonmetals, and is also known as a semimetal. These elements are often semiconductors and have a metallic luster but are brittle. Common metalloids include boron, silicon, germanium, antimony, and tellurium.

A metalloid is an element that possesses a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals, and which is therefore hard to classify as either a metal or a nonmetal.

Metalloids are solids that have both metallic and nonmetallic characteristics, such as a shiny, brittle appearance and intermediate electrical conductivity. They are semiconductors, meaning their conductivity falls between that of a metal and a nonmetal. Chemically, they often behave as nonmetals, have intermediate electronegativity and ionization energy, and can form alloys with metals. 

Summary

The word metalloid comes from the Latin metallum ("metal") and the Greek oeidḗs ("resembling in form or appearance"). However, there is no standard definition of a metalloid and no complete agreement on which elements are metalloids. Despite the lack of specificity, the term remains in use in the literature.

The six commonly recognised metalloids are boron, silicon, germanium, As, antimony and tellurium. Five elements are less frequently so classified: carbon, aluminium, selenium, polonium and astatine. On a standard periodic table, all eleven elements are in a diagonal region of the p-block extending from boron at the upper left to astatine at lower right. Some periodic tables include a dividing line between metals and nonmetals, and the metalloids may be found close to this line.

Typical metalloids have a metallic appearance, may be brittle and are only fair conductors of electricity. They can form alloys with metals, and many of their other physical properties and chemical properties are intermediate between those of metallic and nonmetallic elements. They and their compounds are used in alloys, biological agents, catalysts, flame retardants, glasses, optical storage and optoelectronics, pyrotechnics, semiconductors, and electronics.

The term metalloid originally referred to nonmetals. Its more recent meaning, as a category of elements with intermediate or hybrid properties, became widespread in 1940–1960. Metalloids are sometimes called semimetals, a practice that has been discouraged, as the term semimetal has a more common usage as a specific kind of electronic band structure of a substance. In this context, only As and Sb are semimetals, and commonly recognised as metalloids. 

Details

A metalloid is a chemical element with properties that fall between those of metals and nonmetals. The term typically refers to a group of between six and eight elements—boron, silicon, Ge, As, Sb, tellurium, and possibly, polonium and astatine—found near the center of the P-block or main block of the periodic table. These elements are classified as metalloids because they share certain physical characteristics with metals, such as luster or moderate conductivity, while they exhibit chemical behavior similar to nonmetals—often forming covalent bonds and acidic oxides.

Properties:

Physical properties

* Appearance: They exhibit a metallic luster, giving them a shiny appearance. However, like nonmetals, they are brittle and can shatter under stress.
* Electrical conductivity: They generally act as semiconductors, meaning that they can conduct electricity under certain conditions—this property makes them essential in electronic and photovoltaic devices.
* Thermal conductivity: Their ability to conduct heat falls between that of metals and nonmetals; they are better thermal conductors than nonmetals but not as efficient as metals.
* Density and melting and boiling points: Metalloids usually have densities and melting and boiling points that are intermediate between those of metals and nonmetals, contributing to their classification as a distinct group.
* Allotropy: Metalloids exist in allotropes (multiple structural forms), such as silicon, which appears as amorphous silicon, a brown powder, and crystalline silicon, which has a metallic luster and gray color.

Chemical properties

* Oxidation states: Each metalloid can exhibit more than one oxidation state, which allows these elements to form a wide range of chemical compounds.
* Electronegativity: Metalloids have electronegativity values that fall between those of metals and nonmetals. Metals are generally less electronegative and tend to form ionic compounds, whereas nonmetals are more electronegative and tend to form covalent bonds. Because metalloids sit in the intermediate range, they can form either ionic or covalent bonds, depending on the element with which they react.
* Acid-base behavior: Metals generally react with acids and nonmetals with bases. Metalloids are often amphoteric, meaning that they can react with both acids and bases.

Uses

Metalloids are used in several industries. In electronics silicon and germanium are used as semiconductors in devices such as computer chips, solar cells, and transistors. In glass and ceramics, boron and silicon improve strength and resistance to thermal shock. Borosilicate glass, which includes boron, is used in laboratory equipment and cookware.

Metalloids contribute to alloy production. Silicon is added to aluminum for better casting properties, while boron strengthens steel. Sb and As are used in lead alloys for batteries, bullets, and solders. Antimony compounds also serve as flame retardants.

Additional Information

Some elements are “none of the above.” They don’t fit neatly into the categories of metal or non-metal because of their characteristics. A metalloid is an element that has properties that are intermediate between those of metals and nonmetals. Metalloids can also be called semimetals. On the periodic table, the elements colored yellow, which generally border the stair-step line, are considered to be metalloids. Notice that aluminum borders the line, but it is considered to be a metal since all of its properties are like those of metals.

Examples of Metalloids

Silicon is a typical metalloid. It has luster like a metal, but is brittle like a nonmetal. Silicon is used extensively in computer chips and other electronics because its electrical conductivity is in between that of a metal and a nonmetal.

Boron is a versatile element that can be incorporated into a number of compounds. Borosilicate glass is extremely resistance to thermal shock. Extreme changes in the temperature of objects containing borosilicates will not create any damage to the material, unlike other glass compositions, which would crack or shatter. Because of their strength, boron filaments are used as light, high-strength materials for airplanes, golf clubs, and fishing rods. Sodium tetraborate is widely used in fiberglass as insulation and also is employed in many detergents and cleaners.

Antimony is a brittle, bluish-white metallic material that is a poor conductor of electricity. Used with lead, antimony increases the hardness and strength of the mixture. This material plays an important role in the fabrication of electronic and semiconductor devices. About half of the antimony used industrially is employed in the production of batteries, bullets, and alloys.

Nonmetal

Gist

A nonmetal is a chemical element that lacks the properties of a metal, such as being a poor conductor of heat and electricity and being brittle when solid. Nonmetals can be gases (like oxygen and helium), a liquid (like bromine), or solids (like carbon and sulfur). They tend to have high electronegativity, meaning they attract electrons in chemical reactions.

The 22 nonmetals are hydrogen, helium, carbon, nitrogen, oxygen, fluorine, neon, phosphorus, sulfur, chlorine, argon, selenium, bromine, krypton, iodine, xenon, astatine, radon, tennessine, oganesson, silicon, and boron. Note that silicon and boron are sometimes categorized differently, and the exact classification of the newest elements can vary, but these 22 are commonly listed as nonmetals. 

Summary

A nonmetal, in physics, is a substance having a finite activation energy (band gap) for electron conduction. This means that nonmetals display low (insulators) to moderate (semiconductors) bulk electrical conductivities, which increase with increasing temperature, and are subject to dielectric breakdown at high voltages and temperatures. Like metals, nonmetals may occur in the solid, liquid, or gaseous state. However, unlike metals, nonmetals display a wide range of both mechanical and optical properties, ranging from brittle to plastic and from transparent to opaque.

From a chemical point of view, nonmetals may be divided into two classes: 1) covalent materials, which contain atoms having small sizes, high electronegativities, low valence vacancy to electron ratios, and a pronounced tendency to form negative ions in chemical reactions and negative oxidation states in their compounds; 2) ionic materials, which contain both small and large atoms. Ions may be formed by adding electrons to (small, electronegative atoms) or by extracting electrons from (large, electropositive) atoms. In ionic materials, nonmetals exist either as monatomic anions (e. g., F-in NaF) or as constituents of polyatomic anions (e.g., N and O in the NO3-`s in NaNO3). When in the form of simple elemental substances, about 25 or 22% of the known elements form nonmetals at normal temperatures and pressures, including all of the elements in the S-block of the periodic table and approximately 58% of those in the P-block.

Details

In the context of the periodic table, a nonmetal is a chemical element that mostly lacks distinctive metallic properties. They range from colorless gases like hydrogen to shiny crystals like iodine. Physically, they are usually lighter (less dense) than elements that form metals and are often poor conductors of heat and electricity. Chemically, nonmetals have relatively high electronegativity or usually attract electrons in a chemical bond with another element, and their oxides tend to be acidic.

Seventeen elements are widely recognized as nonmetals. Additionally, some or all of six borderline elements (metalloids) are sometimes counted as nonmetals.

The two lightest nonmetals, hydrogen and helium, together account for about 98% of the mass of the observable universe. Five nonmetallic elements—hydrogen, carbon, nitrogen, oxygen, and silicon—form the bulk of Earth's atmosphere, biosphere, crust and oceans, although metallic elements are believed to be slightly more than half of the overall composition of the Earth.

Chemical compounds and alloys involving multiple elements including nonmetals are widespread. Industrial uses of nonmetals as the dominant component include in electronics, combustion, lubrication and machining.

Most nonmetallic elements were identified in the 18th and 19th centuries. While a distinction between metals and other minerals had existed since antiquity, a classification of chemical elements as metallic or nonmetallic emerged only in the late 18th century. Since then about twenty properties have been suggested as criteria for distinguishing nonmetals from metals. In contemporary research usage it is common to use a distinction between metal and not-a-metal based upon the electronic structure of the solids; the elements carbon, As and Sb are then semimetals, a subclass of metals. The rest of the nonmetallic elements are insulators, some of which such as silicon and germanium can readily accommodate dopants that change the electrical conductivity leading to semiconducting behavior.

Additional Information

The non-metals are elements on the right of the periodic table. Non-metals can be gases, liquids or solids. Non-metals are dull in colour, not shiny like metals. You can't hammer or shape a non-metal; it will just shatter if you hit it. Sulphur is an example of a non-metal. It's yellow and shatters if you hit it with a hammer. Non-metals don't conduct electricity well: they are insulators. There is one exception: graphite is a non-metal which can conduct electricity.

Oxygen, carbon, sulfur and chlorine are examples of non-metal elements.

Non-metals have properties in common with each other. For example, they are often:

* Poor conductors of heat and electricity
* Dull in their appearance
* Weak and brittle

Some other common properties of non-metals are:

* Generally low melting and boiling points, meaning they are gases and liquids at room temperature
* Not sonorous
* Diamond is a form of carbon. Carbon is a non-metal. In the form of diamond it has a high melting point and is shiny.

Some non-metals do not have all of these common properties.

For example, carbon has two main forms - graphite found in pencils, and diamond. Both graphite and diamond have very high melting points and are shiny.

Graphite conducts electricity, which is not typical of non-metals. However graphite is also brittle which is a typical property of non-metals.

Collaborate Quotes

1. Software innovation, like almost every other kind of innovation, requires the ability to collaborate and share ideas with other people, and to sit down and talk with customers and get their feedback and understand their needs. - Bill Gates

2. When you know people are really at peace with who they are and what they do, they collaborate and want to help you to improve. - Javier Bardem

3. I'm one that likes to collaborate. - Christina Aguilera

4. I like to collaborate on my music. The creative process is fun, and you get a lot of ideas from having discussions about it. Ultimately, the final decision is mine. - Janet Jackson.

Q: What do you call dancing candy?
A: Sour cabbage patch kids.
* * *
Q: Why did the grocery store sell green and purple cabbage?
A: Cause two heads are better than one.
* * *
Q: What do you call a man who gives a cabbage a job?
A: A Head hunter.
* * *
Knock, knock!
Who’s there?
Cabbage.
Cabbage who?
What, you expect a cabbage to have a last name or what?
* * *

Nuclear Power

Gist

Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants.

Nuclear power is generated through a process called nuclear fission, where the heat produced is used to create steam that spins turbines to generate electricity. First, neutrons split uranium atoms in a reactor's core, releasing more neutrons and heat. This heat boils water into steam, which then turns a turbine connected to an electric generator. 

Summary

Nuclear power is electricity generated by power plants that derive their heat from fission in a nuclear reactor. Except for the reactor, which plays the role of a boiler in a fossil-fuel power plant, a nuclear power plant is similar to a large coal-fired power plant, with pumps, valves, steam generators, turbines, electric generators, condensers, and associated equipment.

World nuclear power

Nuclear power provides almost 15 percent of the world’s electricity. The first nuclear power plants, which were small demonstration facilities, were built in the 1960s. These prototypes provided “proof-of-concept” and laid the groundwork for the development of the higher-power reactors that followed.

The nuclear power industry went through a period of remarkable growth until about 1990, when the portion of electricity generated by nuclear power reached a high of 17 percent. That percentage remained stable through the 1990s and began to decline slowly around the turn of the 21st century, primarily because of the fact that total electricity generation grew faster than electricity from nuclear power while other sources of energy (particularly coal and natural gas) were able to grow more quickly to meet the rising demand. This trend appears likely to continue well into the 21st century. The Energy Information Administration (EIA), a statistical arm of the U.S. Department of Energy, has projected that world electricity generation between 2005 and 2035 will roughly double (from more than 15,000 terawatt-hours to 35,000 terawatt-hours) and that generation from all energy sources except petroleum will continue to grow.

In 2012 more than 400 nuclear reactors were in operation in 30 countries around the world, and more than 60 were under construction. The United States has the largest nuclear power industry, with more than 100 reactors; it is followed by France, which has more than 50. Of the top 15 electricity-producing countries in the world, all but two, Italy and Australia, utilize nuclear power to generate some of their electricity. The overwhelming majority of nuclear reactor generating capacity is concentrated in North America, Europe, and Asia. The early period of the nuclear power industry was dominated by North America (the United States and Canada), but in the 1980s that lead was overtaken by Europe. The EIA projects that Asia will have the largest nuclear capacity by 2035, mainly because of an ambitious building program in China.

A typical nuclear power plant has a generating capacity of approximately one gigawatt (GW; one billion watts) of electricity. At this capacity, a power plant that operates about 90 percent of the time (the U.S. industry average) will generate about eight terawatt-hours of electricity per year. The predominant types of power reactors are pressurized water reactors (PWRs) and boiling water reactors (BWRs), both of which are categorized as light water reactors (LWRs) because they use ordinary (light) water as a moderator and coolant. LWRs make up more than 80 percent of the world’s nuclear reactors, and more than three-quarters of the LWRs are PWRs.

Details

Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as Voyager 2. Reactors producing controlled fusion power have been operated since 1958 but have yet to generate net power and are not expected to be commercially available in the near future.

The first nuclear power plant was built in the 1950s. The global installed nuclear capacity grew to 100 GW in the late 1970s, and then expanded during the 1980s, reaching 300 GW by 1990. The 1979 Three Mile Island accident in the United States and the 1986 Chernobyl disaster in the Soviet Union resulted in increased regulation and public opposition to nuclear power plants. Nuclear power plants supplied 2,602 terawatt hours (TWh) of electricity in 2023, equivalent to about 9% of global electricity generation, and were the second largest low-carbon power source after hydroelectricity. As of November 2025, there are 416 civilian fission reactors in the world, with overall capacity of 376 GW, 63 under construction and 87 planned, with a combined capacity of 66 GW and 84 GW, respectively. The United States has the largest fleet of nuclear reactors, generating almost 800 TWh per year with an average capacity factor of 92%. The average global capacity factor is 89%. Most new reactors under construction are generation III reactors in Asia.

Nuclear power is a safe, sustainable energy source that reduces carbon emissions. This is because nuclear power generation causes one of the lowest levels of fatalities per unit of energy generated compared to other energy sources. "Economists estimate that each nuclear plant built could save more than 800,000 life years." Coal, petroleum, natural gas and hydroelectricity have each caused more fatalities per unit of energy due to air pollution and accidents. Nuclear power plants also emit no greenhouse gases and result in less life-cycle carbon emissions than common sources of renewable energy. The radiological hazards associated with nuclear power are the primary motivations of the anti-nuclear movement, which contends that nuclear power poses threats to people and the environment, citing the potential for accidents like the Fukushima nuclear disaster in Japan in 2011, and is too expensive to deploy when compared to alternative sustainable energy sources.

Additional Information

As the world’s second-largest source of low-emissions electricity after hydropower, nuclear power today produces just under 10% of global electricity supply. Now, fresh momentum around the world has the potential to open a new era for nuclear energy.

Power generation from the global fleet of nearly 420 active nuclear reactors is set to reach a record high in 2025 as Japan restarts production, maintenance works are completed in France, and new reactors begin commercial operations in various markets, including China, Europe, India and Korea. Meanwhile, more than 60 nuclear reactors are currently under construction – representing over 70 gigawatts (GW) of capacity – and governments’ interest in nuclear power is at its highest level since the oil crisis in the 1970s, reflecting efforts to bolster energy security, accelerate clean energy transitions and meet rising demand for electricity. Over 40 countries now have plans to expand its use.

Nuclear power is an important low-emission source of electricity, providing about 10% of global electricity generation. For those countries where it is accepted, it can complement renewables in reducing power sector emissions while also contributing to electricity security as a dispatchable power source. It is also an option for producing low-emission heat and hydrogen. 

More efforts are needed to get nuclear power on track with the Net Zero Emissions by 2050 Scenario. Lifetime extensions of existing nuclear power plants are one of the most cost-effective sources of low-emission electricity, and there have been several positive policy developments to take full advantage of these opportunities including in the United States, France and Japan. Additional effort is needed to accelerate new constructions – 8 GW of new nuclear capacity was brought online in 2022, but the Net Zero Scenario calls for over four-times as much annual deployment by 2030. Support for innovation in nuclear power, including small modular reactors, will also help expand the range of low-emission options and widen the path to net zero power.

Cold Quotes - VI

1. We're no longer in the Cold War. Eavesdropping on friends is unacceptable. - Vladimir Putin

2. Construction of the first gas pipeline system was started during the 1960s, at the height of the Cold War, and for all those years, from the 1960s until this day, Russia has been fulfilling its contract obligations in a very consistent and reliable way, regardless of the political situation. - Vladimir Putin

3. Well, my friend, this earth will one day be that cold corpse; it will become uninhabitable and uninhabited like the moon, which has long since lost all its vital heat. - Jules Verne

4. I don't plan to take a formal, cold approach with my children, but I expect a lot. I don't want my children to view me as their best friend. I want to be their mom. - Ivanka Trump

5. The cold, commercial word 'market' disguises its human character - a market is a collection of our aspirations, exertions, choices and desires. - Rupert Murdoch

6. If a patient is cold, if a patient is feverish, if a patient is faint, if he is sick after taking food, if he has a bed-sore, it is generally the fault not of the disease, but of the nursing. - Florence Nightingale

7. We've always had this experience that things take long, but I'm 100% convinced that our principles will in the end prevail. No one knew how the Cold War would end at the time, but it did end. This is within our living experience... I'm surprised at how fainthearted we sometimes are and how quickly we lose courage. - Angela Merkel

8. I think I'm teaching my teammates that they can still be successful while having fun and enjoying the moment rather than being a stone cold brick. - Simone Biles.

Q: What water yields award winning cabbage heads?
A: Perspiration!
* * *
Q: What is another name for brussels sprouts?
A: Cabbage patch kids.
* * *
Q: What does a cabbage outlaw have?
A: A price on his head.
* * *
Q: What do you call a cabbage that's in love?
A: Head over heels.
* * *
Q: What do you tell a cabbage that's down in the dumps?
A: Hold your head up high.
* * *