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 ...

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 ...

Students will learn how to categorize matter as either pure substances or mixtures. Students will apply tests, based on physical properties of matter samples, to determine whether a mixture is ...

What is Atom and Molecule? Atoms and molecules are an important part of science and the building blocks of matter. Understanding them is the foundation for understanding all branches of science.

Chemistry: Elements, Compounds, and Mixtures (2nd Edition) (1983) is a 20-minute educational film from the *Chemistry Series* by Coronet Instructional Films, distributed by Simon and Schuster.

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 ...

TimesMachine is an exclusive benefit for home delivery and digital subscribers. About the Archive This is a digitized version of an article from The Times’s print archive, before the start of online ...