Everything we can see and touch, and quite a lot that we can’t as well, is made of tiny particles called atoms. Some substances, like particles of this iron, contain only one kind of atom. Iron is an ...

In this video excerpt from NOVA's "Hunting the Elements," New York Times technology columnist David Pogue investigates chemical reactions involving sodium. Find out how the electron configuration of ...

Chemical reactions occur when elements or compounds combine and create new compounds. Elements are substances that contain only one type of atom and are represented by unique symbols on the periodic ...

Chalk is a fine-textured form of limestone. It is composed of several tiny fragments of the calcite shells or skeletons of ...

This article brings you the CBSE Class 9 Science Notes for Chapter 3 - Atoms and Molecules. These chapter notes are prepared by the subject experts and cover every important topic from the chapter. In ...

Closed electron shell systems, such as hydrogen, nitrogen or group 18 elements, can form weakly bound stoichiometric compounds at high pressures. An understanding of the stability of these van der ...

There are lots of different substances but only just over a hundred elements. An element is a substance that is made up of only one kind of atom. The atoms in a particular element are the same as each ...