You probably don't think about oxygen much unless you're underwater or hiking up a mountain. It’s just there. It’s the invisible stuff keeping us alive, making up about 21% of the air we breathe. But in the world of chemistry, oxygen is a bit of a bully. It’s aggressive. It wants electrons, and it wants them now. When you start looking for what element shares properties with oxygen why it behaves that way, you quickly realize it isn't a mystery. You just have to look directly down on the periodic table.
Meet sulfur.
If oxygen is the clean-cut hero of the story, sulfur is its gritty, smells-like-rotten-eggs cousin. They live in the same neighborhood—specifically Group 16, also known as the chalcogens. Because they sit in the same vertical column, they share a fundamental "DNA" in their electron shells. This isn't just a classroom trivia point. This relationship is why your hair has shape, why deep-sea vents can support life without sunlight, and why some batteries might soon ditch expensive metals for common yellow dust.
The Shared Chemistry of Group 16
Chemistry is basically just a game of musical chairs with electrons. Elements want to be stable. For oxygen and sulfur, stability means having eight electrons in their outermost shell. Currently, they both have six.
That "missing two" is the secret sauce.
Because they both need two more electrons to feel complete, they form similar types of bonds. Oxygen loves to grab two hydrogens to make $H_{2}O$. Sulfur does the same to create $H_{2}S$ (hydrogen sulfide). If you’ve ever smelled a swamp or a stink bomb, you’ve met hydrogen sulfide. While water is the "solvent of life," $H_{2}S$ is often toxic to us, yet it serves as the foundation for entire ecosystems at the bottom of the ocean.
Sulfur is the big brother here. While oxygen is small and compact, sulfur has an extra layer of electrons. This makes it "squishier" or more polarizable in nerd-speak. This slight difference in size is why oxygen is a gas at room temperature while sulfur is a brittle, yellow solid. Oxygen molecules are happy just pairing up as $O_{2}$ and floating away. Sulfur is more social; it prefers to hang out in rings of eight atoms ($S_{8}$), which makes it heavy enough to stay put on the ground.
Why Sulfur and Oxygen Swap Places in Biology
Nature is incredibly efficient. Sometimes, it uses sulfur as a direct "upgrade" or alternative to oxygen because of their shared properties.
Take your hair, for example. It’s made of a protein called keratin. This protein contains an amino acid called cysteine, which features a sulfur atom. These sulfur atoms find each other and form "disulfide bridges." These are basically chemical staples that hold your hair's shape. If you've ever had a "perm," the stylist used chemicals to break those sulfur bonds and reset them. Oxygen doesn't do this nearly as well. Sulfur’s ability to form these sturdy links is something oxygen simply can't replicate despite their similarities.
Then there’s the weird stuff.
📖 Related: Why New Pictures of Mars Still Look So Weird to Us
In the 1970s, scientists found hydrothermal vents on the ocean floor. It was pitch black. No sun. No plants. No photosynthesis. Yet, there were giant tube worms and crabs everywhere. How? Instead of using oxygen and sunlight, the bacteria there used sulfur. They perform "chemosynthesis." They break down hydrogen sulfide—that stinky gas—to create energy. This is only possible because sulfur shares the same "valency" (bonding capacity) as oxygen. It’s a chemical substitute that allowed life to find a loophole in a place where oxygen was scarce.
The Technological Leap: From Air to Batteries
We are currently obsessed with lithium-ion batteries. They power your phone, your laptop, and your Tesla. But they have a ceiling.
Engineers are looking at what element shares properties with oxygen why we can use it to store more power. This leads us back to the oxygen-sulfur connection. Scientists have been experimenting with Lithium-Oxygen ($Li-O_{2}$) and Lithium-Sulfur ($Li-S$) batteries.
Why? Because both elements are light and can pack a massive energy punch.
Lithium-sulfur batteries are the "holy grail" for some researchers. Sulfur is dirt cheap. It’s a byproduct of oil refining, and we have mountains of it just sitting around. Because it reacts similarly to oxygen, it can hold a lot of charge. However, sulfur has a nasty habit of dissolving into the battery fluid (the "shuttle effect"), which makes the battery die quickly. Solving this "shuttle" problem is the current frontline of battery tech. If we win, your phone might stay charged for a week.
Misconceptions About the Chalcogen Family
People often assume that if elements are in the same group, they are interchangeable. That's a dangerous guess.
- The Toxicity Trap: You need oxygen to live. You breathe it. But if you try to "breathe" sulfur (in the form of sulfur dioxide or hydrogen sulfide), your lungs will fail.
- The Smell Factor: Pure oxygen has no smell. Pure sulfur actually doesn't smell much either! The "sulfur smell" people complain about is usually sulfur bonded with hydrogen or carbon.
- The Combustion Difference: Oxygen is the ultimate fuel for fire. While sulfur can burn (creating a blue flame and choking fumes), it doesn't support life-sustaining combustion in the same way.
Honestly, the biggest difference comes down to "electronegativity." Oxygen is the second most electronegative element on the entire periodic table. It is a greedy electron hog. Sulfur is much more chill. It’s willing to share its electrons more easily, which is why it can form a wider variety of weird chemical structures that oxygen wouldn't dream of.
The Rest of the Family: Selenium and Tellurium
If you go even further down the column, you hit Selenium.
Selenium is the "middle child" that actually shares even more specific electronic behaviors with sulfur. It’s used in glass making and even in some dandruff shampoos. Then there’s Tellurium, which is rare and mostly used in solar panels.
The further down you go, the more "metallic" the elements become. Oxygen is a pure gas. Sulfur is a non-metal solid. By the time you get to Tellurium, it looks like a shiny metal, even though it still tries to act like oxygen. This "family resemblance" fades as the atoms get fatter and heavier, but the core rule—needing those two electrons—remains the governing law of their existence.
Real-World Applications You Can See
You can actually see this chemistry in your kitchen. Ever wonder why a silver spoon turns black when it touches eggs?
Eggs are loaded with sulfur proteins. Because sulfur is "isoelectronic" (has similar electron needs) to oxygen, it attacks the silver. While oxygen creates "tarnish" (silver oxide) over a long time, sulfur reacts much faster to create silver sulfide. That black film is literally a chemical manifestation of sulfur acting out its oxygen-like desires on your cutlery.
In the world of wine, winemakers use sulfur dioxide ($SO_{2}$) to keep wine from spoiling. It acts as a preservative because it "mimics" certain oxidative processes but actually prevents oxygen from ruining the flavor. It’s using one family member to block the other from the party.
Leveraging This Knowledge
Understanding what element shares properties with oxygen why gives you a massive leg up in understanding how the physical world is constructed. It’s not just for chemists. If you're in the tech industry, you're looking at sulfur for the next generation of energy storage. If you're in skincare, you're looking at sulfur’s antimicrobial properties (which it shares with oxygen's ability to kill certain bacteria) to treat acne.
To really wrap your head around this, try these steps:
- Check your labels: Look for "sulfates" or "sulfites" in your food and shampoo. Notice how these compounds often replace or interact with "oxides."
- Observe the tarnish: If you have silver or copper items, watch how they react to different environments. High-sulfur environments (like near a gas stove) will darken metal much faster than "clean" air.
- Think in columns: Next time you look at a periodic table, don't look across the rows. Look at the columns. That’s where the real family drama—and the most useful chemistry—actually happens.
The relationship between oxygen and sulfur is a perfect example of how nature repeats its successful patterns. They are two versions of the same idea, one optimized for the air and the other for the earth. Knowing how to swap them is what drives modern material science forward.
Next Steps for Exploration
- Investigate Lithium-Sulfur Research: Check out recent publications from the Department of Energy (DOE) regarding the "shuttle effect" in $Li-S$ batteries. It is the single biggest hurdle to 500-mile EV ranges.
- Study Deep-Sea Biology: Look into the "Woodfall" or "Whalefall" ecosystems where sulfur-reducing bacteria create the base of the food chain in the absence of oxygen.
- Explore Cysteine Bonds: If you are interested in biology or health, research how glutathione—a major antioxidant in your body—relies on its sulfur "thiol" group to neutralize toxins. It’s a direct result of sulfur's unique reactivity compared to oxygen.