Biology
Fatty Acids Explained: Types, Functions, and Food Sources
October 22, 2026
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Biology
Fatty Acids Explained: Types, Functions, and Food Sources
October 22, 2026
Biology
Pollinating Insects: Who Does the Work and How
October 22, 2026
Chemistry
Types of Organic Reactions: How to Spot Each One
October 22, 2026
Chemistry
Erbium Compounds: Colors, Uses, and Why They’re Pink
October 22, 2026
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Books and gear for science readers, students and classrooms, with the specs and editions checked for every pick.
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Periodic tables, conversion charts and worksheets as free PDFs in US Letter and A4, with answer keys for the quizzes.
Weight Conversion Chart
Kilograms to pounds and pounds to kilograms for every body weight, plus ounces, grams and a units table.
Height Conversion Chart
Feet and inches to cm and cm to feet and inches, from 4 to 7 feet, with meters on every row.
Printable Periodic Table
Free periodic table PDFs in color, black and white, blank with a key, kids and an element list, plus a build-your-own customizer.
Fresh from the lab
Chemistry
Vanadium-Producing Countries: Who Mines It and How
China produces roughly 70,000 tonnes of vanadium a year, about 70% of the world’s supply. Russia is a…
October 22, 2026
Biology
Pathogens Explained: Types, Spread and How They Harm
A pathogen is any microorganism or infectious agent that causes disease in a host. That covers bacteria, viruses,…
October 22, 2026
Biology
Birds of Rodrigues: Survivors and Lost Species
Rodrigues is a 108 km² volcanic island in the Indian Ocean, about 560 km east of Mauritius. Two…
October 22, 2026
Earth Science
Glaciology Topics: 8 Branches of Ice Science Explained
Glaciology is the study of ice that moves, melts and remembers. That covers a mountain glacier shrinking above…
October 22, 2026
Geography
Minerals in Ghana: What It Mines and Where
Table of contents TLDR Gold dominates. It accounts for roughly 90 to 95 percent of Ghana’s mineral export…
October 20, 2026
Chemistry
Uses of Krypton: What the Noble Gas Actually Does
TLDR The main uses of krypton are lighting (fluorescent tubes, photographic flashes, high-intensity bulbs), insulating gas inside high-end…
October 20, 2026
Geography
Minerals in Kuwait: What the Country Actually Produces
Contents TLDR Kuwait has almost no metal mining. No gold, iron ore or copper mine of any size…
October 20, 2026
Chemistry
Examples of Organic Compounds, Sorted by Class and Use
An organic compound is a molecule built on a carbon skeleton, almost always with carbon-hydrogen bonds. Methane, ethanol,…
October 20, 2026
Astronomy
11 Myths About Astrophysics That Aren’t True
Most myths about astrophysics survive because they sound reasonable. A black hole has strong gravity, so it must…
October 20, 2026
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33Science is an independent publication exploring the natural world — from the chemistry of a single crystal to the life cycle of a star. Clear, curious and rigorously sourced, for readers of every background.
