Chemistry
Uses of Nickel: Where This Metal Actually Ends Up
October 26, 2026
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Chemistry
Uses of Nickel: Where This Metal Actually Ends Up
October 26, 2026
Biology
Non-Flowering Plants: Mosses, Ferns, Conifers and More
October 26, 2026
Biology
20 Facts About Frogs That Sound Fake (but Aren’t)
October 26, 2026
Earth Science
Natural Resources in New Mexico: Oil, Water and Wind
October 26, 2026
Before you buy
Books and gear for science readers, students and classrooms, with the specs and editions checked for every pick.
Free to print
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
Technology
Tools Used by Data Scientists: The Stack That Matters
Most data scientists spend their days in five things: Python, SQL, a notebook, Git, and a way to…
October 26, 2026
Biology
Non-vascular Plants: Mosses, Liverworts and Hornworts
Non-vascular plants are plants without xylem and phloem, the internal plumbing that moves water and sugars around larger…
October 26, 2026
Geography
10 Caves in Russia, From Ice Palaces to Monastery Tunnels
Russia’s caves aren’t concentrated in one place. They run from the gypsum hills of the Urals to the…
October 26, 2026
Ecology
Types of Biodiversity Measurement and When to Use Each
“How biodiverse is this place?” sounds like one question. It’s at least four, and each one gets a…
October 26, 2026
Biology
Camouflaged Animals: 15 Masters of Hiding in Plain Sight
Contents Camouflaged animals survive by being hard to see, or by being seen as something that isn’t food.…
October 26, 2026
Environment
Branches of Environmental Science: A Clear Guide
Environmental science is the study of how the physical, chemical and biological parts of the planet interact with…
October 22, 2026
Biology
Fatty Acids Explained: Types, Functions, and Food Sources
A fatty acid is a molecule made of a carboxyl group (-COOH) attached to a chain of carbon…
October 22, 2026
Biology
Pollinating Insects: Who Does the Work and How
Table of Contents The main groups of pollinating insects Five groups do most of the pollinating: bees, flies,…
October 22, 2026
Chemistry
Types of Organic Reactions: How to Spot Each One
Nearly every organic reaction you’ll meet in a first course is a variation on four moves: atoms get…
October 22, 2026
Why we publish
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.
