Tag Archives: Atoms

How is Steel Made? The Process Explained

Steel Columns and beams of 1 World Trade Center
Steel columns and beams of One World Trade Center Under Construction. 3/5/2010. Photo: © SMS

Walk down any city construction site and you’re bound to see a network of steel beams and columns rising from the ground. Why are they using steel? Because steel is strong, durable, and easy to work with. It is the iron alloy of choice for building construction. 

If you’re wondering how steel is manufactured, wonder no more! In this blog post, we’ll explain the process from start to finish. 

History of Steel

The emergence of steel can be traced back to the Iron Age when it is used to make swords.  History experts say that the original creators of steel were the Hittites, a middle-eastern civilization that existed during the Bronze Age and later into the Iron age, between 1400 and 1200 B.C. in what is now Syria and Turkey. They learned that by heating iron with carbon, a stronger metallic substance could be made.

Historians are not exactly sure what happened to the Hittites, but the consensus is that they most likely morphed into the Neo-Assyrian Empire (912 to 612 BC).

It has also been discovered that China had first worked with steel around 403–221 BC. and the Han dynasty (202 BBC—AD220) melted wrought iron with cast iron, producing a steel composite.

Modern Day Uses

With the advent of the railroad construction boom in the 19th century and its ongoing requirement for metal to make the tracks, a supply issue was materializing. The process was slow and tedious due since there wasn’t any automatic process to fill the need.

Enter the Steel Mill

Steel mills provided the raw materials for many of the world’s most important products. Since the first mill opened in the early 1800s, they were constantly improved and adapted to meet the needs of the times.

Bethlehem Steel producing 6" guns
6″ guns are being produced by Bethlehem Steel. Photo: Wikimedia Public Domain, circa 1905

These manufacturing plants have helped build skyscrapers, bridges, and countless other structures. They have also been instrumental in the development of new technologies, solving railway construction issues to assembly lines for other products.

There was no time more profitable for the steel mill than during the industrial revolution which began in the nineteenth century and up to the mid-twentieth century.

And there wasn’t a company more notable to achieve the country’s manufacturing demand than Bethlehem Steel, which provided the product for 125 years starting in 1887.

How Steel is Made

Steel does not grow out of thin air. It begins with the mining of iron ore, which then has to be combined with the element carbon via a blast furnace. Let’s get ma more involved in understanding how this process works.

Mining the Iron Mineral

It all begins with the mining of iron ore. An ore represents a mineral from here a valuable asset can be extracted.

Once it is taken out from the quarry, the ore is melted and purified  (removing impurities from the ore and leaving only the metal). This is done in a blast furnace.

Enter Carbon

Carbon is an element in the Periodic Table that has an atomic number of six, with four electrons in its outer shell and two electrons in its inner shell.

Atoms that have less than eight electrons in their outer shell, (called the valence shell) tend to look for other atoms to bond with so that their outer shells can stabilize the atom by balancing the shell to eight electrons. This is based on the Octet Rule.

Illustration of the carbon atom
Bohr Illustration of the Carbon Atom. Photo: Photo by dacurrier on Pixabay

Iron has eight electrons in its valence shell, so if you bond the carbon atom that has six valence electrons with the iron atom, you have a molecule of two different atoms which forms steel.

It is essential to ensure that the correct amount of carbon is used with iron, approximately 0.04% so that the resultant product is that of steel.

If the wrong amount of carbon is mixed with iron, a different product will be produced such as cast iron or wrought iron – both of these are not efficient to render steel.

When is Carbon Added to Iron?

For steel, the combination of the two elements is done while the iron metal is liquid hot, which then alters the iron’s properties to change to that of steel.

Steel subsequently becomes an alloy (a metal made by combining two or more metallic elements) of iron and carbon.  This causes a distortion of the crystalline lattice structure of iron and subsequently enhances the metal’s strength; specifically, it increases the metal’s tension and compression properties. 

The Manufacturing Process

Steel Cantilever at Chase Bank Headquarters
Steel Cantilever at Chase Bank Headquarters Under Construction, 8/5/2022. Photo: © SMS

A breakthrough for manufacturing steel via an automated process materialized in 1856 when Henry Bessemer found a way to manufacture steel quickly. Bessemer’s steel production process is what inspired the Industrial Revolution. 

It was the first cost-efficient industrial process for the large-scale production of steel from molten pig iron, by taking out impurities from pig iron using an air blast. 

Adding Carbon Produces a Variety of Iron Alloys

As previously mentioned, when mixed with carbon, the iron’s characteristics will be changed, allowing a variety of different types of metal alloys to be created. It all depends upon the amount of carbon that is added to it. Let’s take a look.

Wrought Iron

Wrought iron fence. Palermo Italy
Wrought iron fence. Palermo Italy.
Photo: © SMS

Wrought iron is softer than cast iron and contains less than 0.1 percent carbon and 1 or 2 percent slag.

It was an advancement over bronze and began to replace bronze in Asia Minor by the 2nd century BC. Because iron was far more plentiful as a natural resource, wrought iron was used for a wide variety of implements as well as weapons and armor. 

Cast Iron

Cast iron buildings NYC
Cast iron buildings, Lower Manhattan. Photo: © SMS

Cast iron is an alloy of iron that contains 2 to 4 percent carbon, along with smaller amounts of other elements, such as silicon, manganese, and minor traces of sulfur and phosphorus. These minerals are nonmetallic and are referenced in the industry as slag. Cast iron can be easily molded into a desired shape, known as casting. and has been used to make decorative fences and other aesthetic forms.

Cast iron facades were invented in America in the mid-1800s and were produced quickly, requiring much less time and resources than stone or brick. They were also very efficient for decorative purposes, as the same molds were used for many buildings and a broken piece could be quickly remolded. Because iron is powerful, large windows were utilized, allowing a lot of light into buildings and high ceilings that required only columns for support.


Steel is an alloy made from iron that usually contains several tenths of a percent of carbon, which increases its strength and durability over the other forms of iron, especially in tensile strength.

Strictly speaking, steel is just another kind of iron alloy, but has much lower carbon than cast iron, and about as much carbon (or sometimes slightly more) than working iron, with other metals, frequently added to give it additional properties. 

Most of the steel produced today is called carbon steel, or simple carbon, although it can contain metals other than iron and carbon, like silicon and manganese. 


The advantages of steel are numerous, from great tensile and compression strength to speed of manufacturing to low cost, it is the metal of choice in construction when compared to iron.

 Although iron and steel appear to be similar, they are two distinct materials that have specific characteristics and qualities. Iron is a pure mineral and steel is an alloy material that contains a percentage of carbon.  Depending on the amount of carbon mixed with iron, different products emerge, and this includes creation of steel. 

Steel is a far stronger material and there is no better metal at this time that is used when strength and cost are major factors.


What is the Atom Made of?

Did you ever see the movie “The Incredible Shrinking Man”? If you have, did you ever wonder what would happen to him when he gets so small that he would be the size of an atom? And if so, could he get any smaller?

Maybe we have the answer because atoms are particles that exist in nature that cannot be broken down any further into smaller components. Everything we see around us is made of atoms, from tables and chairs to people and pandas. 

What Makes Up the Atom?

Illustration of the Atom
Atoms consist of three basic particles: protons, electrons, and neutrons. Nucleus. This atom has a neutral charge as it contains the same amount of protons and electrons. Photo: iStock

Comparatively speaking, atoms contain mostly empty space, but don’t let that fool you into thinking they are not important. The components of the atom and what makes up the atom are fundamental to our understanding of how matter is assembled. That includes living organisms, both here on earth and elsewhere. 

Now let’s talk about the components. A typical atom consists of a nucleus in its center. This nucleus contains neutrons and protons (together they’re called nucleons). Protons have a positive charge. Neutrons have neither positive nor negative charges. They are ‘neutral’.

Surrounding the nucleus are electrons, which are bodies outside of the nucleus and orbit around it, the same as our planets orbit their sun. Besides the size difference in this comparison, the only major difference is that the planets orbit the sun because of gravity, and electrons orbit their nucleus because of magnetism.

Note: The above scenario is simplified to vision the structure of the atom. The real fact is that electrons do not orbit the nucleus as the planets do. Their actions are more complex than that. See our article on Quantum Theory for a better understanding of how electrons maneuver around the atom’s nucleus.

The Electron

An electron orbits the nucleus of the atom. They are negatively charged particles. The electrons are the only particles outside of the atom’s nucleus.

Neutral Atoms

A neutral atom doesn’t have any charge, so it doesn’t interact with other atoms. You can think of it as a bag of protons, neutrons, and electrons that just float around in space. Most neutral atoms are made up of an equal number of protons, neutrons, and electrons. For example, hydrogen has one proton, one neutron, and one electron. Helium atoms have two protons, two neutrons, and two electrons. This is why we usually refer to these atoms as neutral.

The Proton 

Periodic table
Image by Calua from Pixabay

Protons are mainly found in the nucleus, although a few may be found in the outer electron orbit. The number of protons in an atom is what makes it what it is. For example, the elements in the periodic table have numbers associated with them. The number on the upper right corner defines its atomic number; that is, it tells us the number of protons in that element. Atomic weight is the number of protons and neutrons together.


The neutron’s only job is to protect the proton from becoming too positively charged. It doesn’t matter if the atom has too many or too few neutrons; it’s fine either way. The neutron doesn’t interact with electrons or anything else outside the nucleus, so it’s usually just along for the ride.

The valence electrons (see below) of an atom are the electrons that are available to form chemical bonds with other atoms. In general, valence electrons are those that can be shared in their atomic orbitals.

Each main group element has a fixed number of valence electrons, which makes it easier to predict how likely an element is to react with another one and whether or not a given element can act as a reducing agent. Combining all of this information, we can deduce the oxidation state (or valence) of each element and predict whether or not they will react with one another based on these findings. Let’s take a closer look at what these valence electrons are and what role they play in chemical reactions.


Any time an atom loses or gains an electron, it becomes charged. If it loses an electron, it becomes positively charged. because there are more protons in the atom than electrons. If it gains an electron, it becomes negatively charged. 

When atoms gain or lose an electron, they can bond together with other ions to form other elements; thereby creating a new atom or molecule.

Note: Regardless of the number of electrons or protons that are lost or gained, the ‘makeup’ of the atom is associated with the number of protons that are in the atom, as designated in the upper right corner of each element of the periodic table. 

So What are Valence Electrons?

Illustration of an atom's valence electrons
Photo: Pixabay

These are electrons that are in the outermost shell of an atom and if these atoms have less than 8 electrons in this shell, they will look to find other atoms to bond with so that their outer shells can reach 8 electrons.

This is the Octet Rule, which states that atoms with less than 8 electrons in their outer shell will tend to bond with other atoms so that they can share their valence shells and have 8 electrons, hence, the “octet (8)” rule.

From our explanation of ions above, it is these electrons that are participating in the chemical reactions (bonding) with other atoms, since they are the farthest away from the nucleus and thus, have the least magnetic force attached to them. In other words, can easily get detached or pulled from a nearby atom.

So, it is these electrons that are the ones that cause the sharing of electrons with other atoms.

Valence Proximity

The electrons that are closer to the nucleus are referred to as core electrons since they aren’t as likely to participate in chemical reactions. The core electrons are essential to the existence of an atom because without them the atom would collapse in on itself. However, they’re not as likely to be involved in chemical reactions with other atoms because they’re so close to the nucleus.

Valence Summary

The valence electrons are the outermost electrons in an atom that is available to form chemical bonds with other atoms. The number of valence electrons for each element is fixed, and we can use the location of these electrons to predict how likely it is for an atom to bond with another. The more stable the core electrons are, the more difficult it will be for an atom to accept its electrons. If you’re studying chemistry and need to understand how chemical reactions work, it’s important to understand what valence electrons are and how they are used during chemical reactions.

All Together Now

The negative charge of the electrons and the positive charge of the protons are what maintain the orbit of the electrons around the nucleus. This is referred to as an electrostatic charge, or electromagnetic force, or to put it another way, it is the attraction of the positive charge from the negative charge of the electrons that causes this orbit to exist.

Now, let’s drill down to more specifics of the atom’s components and how their respective charges make up different types of atoms. 


Atoms are the smallest particles of matter that cannot be broken down into smaller components. Everything we see around us is made of atoms. Atoms are mostly empty spaces, but they’re fundamental to our understanding of how matter works. A typical atom consists of a nucleus with neutrons and protons (together called nucleons) inside it, as well as electrons that orbit the nucleus. The electrons have a negative charge; the nucleons have a positive charge. 

Neutral atoms are made up of an equal number of protons, neutrons, and electrons. Ionic compounds are made up of positively charged ions and negatively charged electrons, and they have a strong attraction to other atoms and molecules. Electrons are negatively charged particles that orbit the nucleus, making them useful tools. Atoms are the building blocks of everything in the universe, and they are fundamental to our understanding of how matter works.