The Laboratory in Blue Prince is home to two puzzles: the periodic table puzzle and the machine puzzle. Both puzzles are ...

As you move down a group in the periodic table, the covalent radius increases ... screen or shield the outer electrons from the nuclear charge.

The “lead” of a pencil is actually made of a substance called graphite which is made of carbon atoms. The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and ...

Browse a list of curated classroom activities by the American Association of Chemistry Teachers. Lesson Plans: The Periodic Table and Bonding Download inquiry-based lesson plans and activity sheets to ...