6 Key Metalloid Properties: Uses In Modern Tech

Have you ever thought about what makes up your smartphone? Or the solar panels on some houses? These things work because of special elements called metalloids. Metalloids sit in the middle of the periodic table. They’re not quite metals, but they’re not quite non-metals either. They have special intermediate properties that make them very useful in today’s technology.

What Are Metalloids?

Metalloids are elements that show both metal and non-metal traits. On the periodic table, you’ll find them along a zigzag line between metals and non-metals. The six most common metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.

These elements help power our digital world. Let’s look at the six key properties that make metalloids so special and useful.

1. Intermediate Electrical Conductivity

One of the most important things about metalloids is they can be semiconductors. This means they conduct electricity in a special way.

How it works:

Metals conduct electricity very well
Non-metals usually don’t conduct electricity
Metalloids are in the middle – they can be made to conduct electricity under certain conditions

Unlike metals, metalloids conduct electricity better when they get warmer. This is the opposite of most metals!

Doping applications are when tiny amounts of other elements are added to metalloids to change how they conduct electricity. For example, adding a bit of phosphorus to silicon creates what’s called “n-type” semiconductors, while adding boron creates “p-type” semiconductors. This process is key to making computer chips and electronic parts.

Real-World Data:

The conductivity of metalloids ranges from 10⁻³ to 10³ S/m, depending on temperature. Silicon wafers make up about 95% of the semiconductor market, showing just how important this property is.

2. Brittle Physical Structure

Unlike metals that can be bent and shaped, metalloids are brittle. This means they tend to break when force is applied to them.

Key points:

They shatter rather than bend
They lack the ductility of metals
They have crystalline structures that break along specific planes

For example, silicon and germanium have a diamond-like crystal structure that makes them hard but easy to break. Arsenic and antimony are also quite brittle. This property affects how we use metalloids in manufacturing.

When making solar cells from silicon, this brittleness creates challenges. Special protective coatings must be applied to prevent the cells from cracking. The manufacturing process for these materials often requires precision machining techniques.

Silicon crystal structure showing metalloid brittleness

3. Variable Metallic Luster

Metalloids have a shine to them, but it’s not as bright as true metals.

What this means:

They might look shiny but don’t reflect light as well as metals
The shine varies among different metalloids
Some look metallic, while others appear more dull

Silicon has a dark, metallic sheen, while tellurium has a more subtle shine. This property isn’t just about looks—it affects how these materials interact with light, which matters for optical applications.

The reflectivity of silicon is about 20-35%, while antimony reflects about 50% of light. This is lower than most true metals, which can reflect up to 95% of light.

4. Amphoteric Chemical Reactivity

Amphoteric means that metalloids can react with both acids and bases. This makes them very versatile in chemical reactions.

For example, silicon reacts with sodium hydroxide (a base) through this reaction: Si + 2NaOH + H₂O → Na₂SiO₃ + 2H₂

But silicon also reacts with hydrofluoric acid (HF). This dual behavior is rare and very useful in chemistry and manufacturing.

This property is especially important for:

Glass etching (using silicon’s reaction with HF)
Making water-resistant materials
Creating special ceramics and compounds

The ability to react in multiple ways makes metalloids key ingredients in many industrial processes. When manufacturing precision parts through processes like CNC milling, understanding these chemical properties is crucial.

5. Thermal Conductivity Duality

Metalloids conduct heat better than non-metals but not as well as metals. This middle-ground property makes them useful in many applications.

Examples:

Boron has a thermal conductivity of 27 W/m·K
Copper (a metal) has 385 W/m·K
Most non-metals have values under 1 W/m·K

This property makes metalloids useful for:

Heat-resistant glass (using boron)
Thermal interface materials (using silicon)
Temperature sensors
Heat management in electronics

Borosilicate glass, which contains boron, can withstand sudden temperature changes without cracking. That’s why it’s used in lab equipment and cookware.

6. Intermediate Ionization Energy

Ionization energy is the energy needed to remove an electron from an atom. Metalloids have ionization energies between those of metals and non-metals.

What this means:

They don’t give up electrons as easily as metals
They don’t hold onto electrons as tightly as non-metals
This affects how they form bonds and react chemically

For example, boron has an ionization energy of about 800 kJ/mol, while aluminum (a metal) has 578 kJ/mol. This difference affects how these elements behave in chemical reactions.

This property also relates to metalloids’ toxicity. Arsenic’s intermediate ionization energy contributes to its toxicity, with an LD₅₀ (lethal dose) of 15-30 mg/kg in humans.

Practical Applications of Metalloid Properties

These six special properties make metalloids extremely useful in our modern world. Here are some key applications:

Electronics and Computing

Silicon in computer chips, solar cells, and transistors
Germanium in fiber optics and night vision technology
Boron doping for semiconductor manufacturing

Silicon’s semiconductor behavior allows for the precise control of electrical signals in devices like computers and smartphones. The global semiconductor market was worth $580 billion in 2023, with silicon driving 95% of production.

Industrial Uses

Antimony in flame retardants and batteries (140,000 tons produced in 2022)
Tellurium in steel to make it easier to shape
Boron in glass production and ceramics
Silicon in CNC machining applications for electronics

Medical Applications

Boron compounds in antiseptics
Arsenic in limited chemotherapy treatments
Silicon in medical implants and devices

Environmental Technology

Silicon in solar cells
Tellurium in solar panels
Boron in agricultural nutrients

Key Case Studies of Metalloid Applications

Silicon in Solar Energy

Silicon’s semi-conductive properties have made it the star of solar energy. While silicon solar cells were only about 15% efficient in 2000, improvements in doping and manufacturing have raised that to 22% by 2023. Today, silicon cells make up 95% of all solar panels worldwide. The brittle structure of silicon remains a challenge, requiring protective glass coverings.

Boron in Nuclear Energy

Boron-10, an isotope of boron, strongly absorbs neutrons. This makes it perfect for nuclear reactor control rods. About 2,500 tons of boron are used yearly in nuclear applications worldwide. Boron’s intermediate properties allow it to function effectively in the extreme conditions inside reactors.

Arsenic in Medicine

Despite being toxic, arsenic trioxide has found a role in treating a specific type of leukemia. Its use demonstrates how the amphoteric behavior of metalloids can be harnessed medicinally when properly controlled. Modern medicine carefully balances arsenic’s toxic effects with its cancer-fighting abilities.

Silicon solar cells demonstrating metalloid semiconductor applications

Comparison of Metalloid Properties

Here’s how metalloids stack up against metals and non-metals:

Property	Metals	Metalloids	Non-metals
Electrical Conductivity	High (10³-10⁵ S/m)	Variable (10⁻³-10³ S/m)	Low (10⁻¹⁰-10⁻⁵ S/m)
Physical Structure	Ductile, malleable	Brittle	Brittle or gaseous
Luster	High shine	Medium shine	No shine
Chemical Reactivity	With acids	With acids and bases	With metals
Thermal Conductivity	High	Medium	Low
Ionization Energy	Low	Medium	High

Why Metalloids Matter

Metalloids are special because they bridge the gap between metals and non-metals. This middle ground gives them properties that are perfect for modern technology.

Silicon alone has transformed our world through:

Computers and smartphones
Solar energy
Medical devices
Advanced machining for precision parts

Without metalloids, we wouldn’t have the digital revolution that defines modern life. Their unique set of properties—from semiconductor applications to their usefulness in creating specialized materials—makes them irreplaceable in today’s technology.

Frequently Asked Questions

Why are metalloids sometimes hard to classify?

Metalloids have overlapping traits with both metals and non-metals. Elements like polonium sit at the boundary and are sometimes classified differently by different scientists. The properties of metalloids exist on a spectrum rather than having clear-cut boundaries.

Which metalloid is the most toxic?

Arsenic is generally considered the most toxic naturally occurring metalloid. It has been used as a poison throughout history. Antimony is also toxic in many of its compounds. The toxicity relates to how these elements interact with biological systems.

Do metalloids conduct electricity?

Yes, but not like metals do. Metalloids are semiconductors, which means they conduct electricity under specific conditions, particularly when “doped” with other elements or when heated. Their conductivity can be precisely controlled, which is why they’re so useful in electronics.

Conclusion

Metalloids are truly special elements with six key properties that make them essential to modern technology. Their intermediate conductivity, brittle structure, variable luster, amphoteric behavior, moderate thermal conductivity, and balanced ionization energy create a unique set of characteristics.

From the silicon in your computer to the boron in heat-resistant glass, metalloids quietly enable much of our technological world. As we continue to develop new technologies, these versatile elements will remain at the heart of innovation.

Understanding these six properties helps us see why metalloids are so important and how they’ll continue to shape our future through advanced manufacturing techniques like precision CNC machining and semiconductor production.