Scientists Say: Plastic

This is a material made of long polymers that is easy to shape — but hard to get rid of

two plastic covered hands held together and palm up are holding lots of small pieces of plastic trash

These are small pieces of plastic trash. Plastic is very tough and can take hundreds of years to break down in the environment.

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Plastic (noun, “PLAS-tick”)

This is a word that describes a wide range of materials that can be molded into many different solid objects. Usually, plastics are made from fossil fuels such as petroleum. But they can also be made from plants such as corn or cotton. Petroleum, corn and cotton are organic. But in chemistry, “organic” has nothing to do with how food is grown. Instead, it means the molecules in the petroleum, corn or cotton contain a lot carbon-hydrogen bonds. Those can be formed into polymers — very long chemical chains. Those chains can then be stuck together to form plastics.

Plastics can come in all shapes and sizes. In fact, “plastic” can also be used as an adjective and mean that something can be formed or shaped easily. Plastics can be extremely strong — such as a Kevlar vest. They can also be very flexible — such as plastic wrap. Unfortunately, plastic is also tough. Often, we rely on microbes to break down our trash, but very few microbes will make a meal out of plastic. So plastic can stay in the environment for hundreds of years, just breaking into smaller and smaller pieces

In a sentence

Legos are made of tough, strong plastic — so strong that ocean animals could be stepping on them on the seafloor for hundreds of years

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.