American Chemical Society (ACS) Collaborate with Scientists form around the world and access chemistry-related resources and tools.
Chemguide Helping students understand chemistry.
Chemical Portal A great aggregating portal for chemistry enthusiasts.
Chemistry World Chemistry, covered. Science news, research, reviews, features and opinions.
Dynamic Periodic Table Interactive periodic table with dynamic insights.
Royal Society of Chemistry (RSC) Advancing excellence, connecting chemical scientists and shaping the future of the chemical sciences for the benefit of humanity.
Apps
Learn Organic Chemistry offers a quick summary of essential concepts in Organic Chemistry: Aldehydes and Ketones, Reaction Mechanisms, Hydrocarbons, Alkynes and Alcohols, Isomerism and Its Types, Organic Acids and Bases, and more. Free for Android devices.
Molecules. Molecules is an application for viewing three-dimensional renderings of molecules and manipulating them using your fingers. Free for iPhone, iPodtouch and iPad.
NOVA Elements App lets you explore an interactive periodic table, build the elements, and play a game. Find out why the periodic table is shaped the way it is, what gives each element its own unique set of properties. Free for iOS and Android devices.
Quick Periodic Table of the Elements Great to quickly refer to for periodic table reference. You may choose from different views, getting full insight on every element, with information like its molar mass, properties and atomic number. Free for iPad and iPhone.