With a plethora of metals existing in all three categories, it can be difficult to keep track of whether a metal is a compound, element, or mixture. Brass, specifically, is often confused for copper or bronze, making this particular metal even more confusing to decipher.
Brass is a mixture made of copper and zinc. Mixtures occur when two metals combine to make a third metal. In this case, copper and zinc come together to make brass. Because brass does not fit the qualifications for a compound or element, the metal is a mixture.
The rest of this article will dig deeper into what makes brass a mixture as opposed to an element or a compound, by exploring the differences and similarities between the three categories. I’ll also delve into how brass differs from other similar metal mixtures.
What Makes Brass a Mixture?
Brass’s categorization as a mixture matters because it’s the main reason brass is an inexpensive alternative to similar, but much pricier metals, such as copper or gold. But what makes this economical choice a mixture instead of anything else?
Simply put, chemists classify a mixture as something that occurs when two elements come together to make something else. To understand what places brass in this particular group, it’s important to know the difference between an element, a compound, and a mixture.
Even metals that may seem similar, such as brass and copper, can vary greatly when it comes to which classification they belong to. For instance, gold is an element, while pyrite, also known as fool’s gold, is a compound.
The category a metal, such as brass, fits in depends on many factors, such as what substances the metal is made of, and whether the percentage of the substances within it can be varied.
Elements Are Their Own Substances
According to a report on elements published by The University of Illinois, “elements are pure substances,” meaning they are not made from any other type of substance. Elements consist of their own individual atoms, causing all elements to be entirely unique.
There are only 100 elements, but they can be combined to make nearly limitless amounts of unique compounds and mixtures that make up our everyday world. Brass is just one example of what can occur when two or more elements are mixed together.
Some examples of metal elements, other than copper and zinc, are:
Because mixtures are made up of multiple elements combined, they can be broken down into smaller parts, unlike elements.
Brass, when broken down, divides into zinc and copper. Therefore, because brass is not a standalone substance, it cannot be considered an element.
To watch zinc and copper combine to make brass, check out this fascinating video:
Watch Hank Green’s Crash Course on The Periodic Table if you are interested in learning more about elements and The Periodic Table:
Compounds Are Chemically Blended
Similarly to mixtures, compounds are made up of more than one element blended together. Compounds, however, are made of elements that are chemically combined, while mixtures are put together physically.
Further, compounds must have an equal percentage of both elements in order to exist.
The Bodner Research Lab at Purdue University explains that water, for example, is a compound because it is always made of exactly 88.8% oxygen and 11.2% hydrogen. Hydrogen Peroxide, as another example of a compound, consists of precisely 94.07% oxygen and 5.93% hydrogen.
Both water and hydrogen peroxide are made up of hydrogen and oxygen, but the specific percentages in each make them entirely different substances. Brass, on the other hand, can exist even with large variations in its percentages of zinc and copper.
Brass, therefore, cannot be qualified as a compound. The percentage of zinc can be extremely low or high compared to the percentage of copper, but as long as the two are combined, they would still combine to create brass.
Additionally, there’s another key difference between mixtures and compounds. While mixtures can be separated easily, a compound must be entirely destroyed in order to be broken into its smaller parts. It would be much easier for brass to be sorted into zinc and copper than for water to be divided into hydrogen and oxygen.
Further, mixtures can actually be made of compounds, while compounds cannot be made of mixtures.
Essentially, it’s not possible for brass to be a compound because:
- Brass can be made of almost any percentage of zinc and copper
- Brass can be easily broken apart
Mixtures Are Physically Blended
Mixtures, unlike compounds, are created by physically combining two or more substances.
A publication by Elmhurst College explains another important distinction. Mixtures can be made of two or more substances, whether compounds or elements. Brass, of course, is made from two pure elements – zinc and copper – but other mixtures exist that are made of compounds.
Other examples of metals that are mixtures are:
- Sterling Silver
- Rose Gold
How Is Brass Different From Other Metal Mixtures?
It may seem obvious that no two mixtures can possibly be the same, but brass is similar enough to other mixtures that it can oftentimes be confused with different metals.
When two mixtures seem similar, it’s usually because they share a common substance – but the substance they don’t have in common is what makes them unique.
Brass and Bronze Are Both Made With Zinc
Brass is often confused with a similar mixture: bronze. Both metals share gold-like colors, but bronze has a much more tarnished shade, while brass tends to be bright and shiny.
The reason brass and bronze are so similar is that they are both mixtures made up of zinc. The only difference is that brass is made with zinc and copper, while bronze is the result of combining zinc with tin.
No Two Mixtures Are the Same
While bronze and brass are strikingly similar, they are proof that mixtures must be made from a specific set of elements in order to exist. While both metals are made with zinc, the seemingly minor difference between tin and copper is the difference between two entirely different metals.
That said, while no two mixtures are exactly the same, they are all made by combining two or more elements or compounds, and they can all be broken down into smaller parts. This is, at its simplest, what differentiates mixtures from compounds and elements.
Check out Professor Dave Explains’ helpful video, “Types of Matter: Elements, Compounds, and Mixtures,” on YouTube for a more complex dive into the three fundamental categories:
Brass is classified as a mixture because:
- It’s made up of two elements
- It can be made from any percentage of those elements
- It can be broken down into two elements and does not stand as its own substance
However, brass differs from other mixtures, such as bronze or rose gold, because it’s made up of specifically zinc and copper. There’s no other possible combination of elements that can produce brass.
While it can be confusing to keep track of the various types of metals, a small amount of research can help to differentiate them in no time at all. Even though the metal may look like an element (copper) and have similar qualifications to compounds, because it’s made up of two elements of any percentage that are physically combined, it’s safe to conclude that brass is a mixture.