What Everyday Objects Are Really Made Of

My niece asked me a question last month that I couldn't stop thinking about: "What's my stuffed elephant actually made of?" I started to say "cotton and polyester," but she cut me off. "No, like what ATOMS?"

That question sent me down a rabbit hole. Here's what I found.

Water: Simpler Than You'd Think

Two hydrogen atoms. One oxygen atom. That's the whole recipe.

But consider this: hydrogen is the lightest element, an explosive gas. Oxygen is what we breathe. Put them together and you get something you can drink without exploding. Chemistry is weird like that.

By mass, water is actually 89% oxygen. The oxygen atom is just that much heavier. So when you drink a glass of water, you're mostly drinking oxygen, just in a form your lungs can't use.

The angle between those two hydrogen atoms (about 104.5 degrees) makes water polar. That's why it dissolves salt but not oil. That's why ice floats. That polarity is why you exist.

The Air You Just Breathed

Most people assume air is mostly oxygen. It's not.

Nitrogen makes up 78% of every breath. Oxygen is only about 21%. The rest is mostly argon (almost 1%) plus traces of carbon dioxide, neon, helium, and other gases.

Here's something to think about: you're breathing atoms that dinosaurs breathed. Nitrogen molecules don't really go anywhere. They cycle around for millions of years. Statistically, some of the nitrogen in your last breath probably passed through a T-Rex at some point.

Wood Is Mostly Oxygen

This surprised me. Before I looked it up, I would have guessed wood was mostly carbon. It's not.

Wood is roughly 50% carbon, 42% oxygen, 6% hydrogen, and small amounts of nitrogen and other elements. More oxygen than carbon.

This makes sense when you think about it: wood is made of cellulose and lignin, which are basically sugar polymers. Sugars contain a lot of oxygen. Trees pull carbon dioxide from the air and water from the ground, then rearrange those molecules into wood. Most of the oxygen stays in place.

When wood burns, you're releasing solar energy that was captured decades ago. The carbon combines with atmospheric oxygen to make CO2, returning to where it started. Trees are slow batteries.

Your Phone Screen: Not Just Glass

Regular window glass is mostly silicon dioxide (sand) mixed with sodium and calcium compounds. But your phone screen is something fancier.

Gorilla Glass and similar screens contain silicon and oxygen (the base), plus aluminum for strength, sodium to lower the melting point, potassium for the hardening process, and magnesium for structural benefits.

The manufacturing process swaps smaller sodium atoms for larger potassium atoms in the surface layer. This creates compression stress that makes the glass surprisingly hard to crack. The chemistry is elegant.

Steel: Iron With a Secret Ingredient

Steel is almost entirely iron. Typically 98-99%.

The remaining 1-2% is what makes the difference. Most of that is carbon. That small percentage matters enormously.

Pure iron is actually pretty soft. Add 0.5% carbon and it hardens significantly. Add 1% and you get high-carbon steel, which holds a sharp edge but can be brittle. Add chromium and you get stainless steel that doesn't rust.

The exact recipe determines whether the steel ends up in a kitchen knife, a bridge support, or a surgical tool.

Table Salt: Two Dangerous Things Made Safe

Sodium chloride is 39% sodium and 61% chlorine by mass.

Think about what you're sprinkling on your food: sodium is a soft metal that explodes on contact with water. Chlorine is a poisonous green gas used as a chemical weapon. Combined, they create an essential nutrient that your body literally cannot function without.

Sodium gives up an electron. Chlorine takes it. Both become stable. They stick together through electrostatic attraction. The violent reaction produced something completely harmless.

Your Body: Mostly Oxygen (Really)

The human body is about 65% oxygen by mass.

Full breakdown:

• Oxygen: 65%
• Carbon: 18.5%
• Hydrogen: 9.5%
• Nitrogen: 3%
• Everything else: 4%

You're mostly oxygen because you're mostly water. Remove all the water, and your dry mass is mostly carbon and nitrogen, the building blocks of proteins and DNA.

Every element in your body heavier than hydrogen was created inside a star. The calcium in your bones, the iron in your blood, the phosphorus in your DNA. All forged in nuclear fusion and scattered across the universe when stars exploded. You're recycled stardust.

Plastic: Just Two Elements, Endless Variations

Most plastics are just carbon and hydrogen arranged in long chains. Polyethylene, the most common plastic, is about 86% carbon and 14% hydrogen.

The difference between a flimsy plastic bag and a sturdy milk jug comes down to how those chains are arranged. High-density polyethylene has straighter chains that pack tightly. Low-density polyethylene has more branching.

Same elements. Same bonds. Different structures. Different properties.

Concrete: More Popular Than You'd Guess

By volume, concrete is the most used material on Earth. A typical batch contains:

• Calcium: 20-25% (from cement)
• Silicon: 15-20% (from sand and aggregate)
• Oxygen: 45-50% (bound in the minerals)
• Aluminum, iron, and traces of other elements

When you add water to cement powder, chemical reactions form calcium silicate hydrate, a gel that hardens into something resembling artificial rock.

The Romans figured this out 2,000 years ago. Their concrete is still standing. Much of our modern concrete is crumbling because we add steel reinforcement that corrodes. They didn't.

The Pattern I Noticed

After looking at dozens of materials, a pattern emerged: most living things and organic materials are dominated by just six elements. Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. Scientists call these the CHNOPS elements.

These six form the foundation of life because they can create stable, complex molecules and they're abundant on Earth.

Meanwhile, rocks and minerals are dominated by silicon and oxygen. These two elements make up about 75% of Earth's crust.

The universe has a surprisingly limited parts list. It just uses those parts in infinite combinations.