Learn about elements, compounds and mixtures in this KS3 Chemistry guide from BBC Bitesize.

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 ...

Atom vs Element vs Molecule vs Compound. The table below explains the differences between the atom, element, molecules and a compound. Check and clear all your doubts related to these four.

Feature. Atomic Mass. Molecular Mass. Definition. The mass of a single atom of an element. The sum of the atomic masses of all the atoms in a molecule.

Promethium bound: fundamental chemistry of an elusive element finally observed. Compounds in which a metal atom contributes to aromaticity are not unusual — the first such ‘metalloaromatic ...

a, Borane compounds, BR 3, have a 'vacancy' — an absence of a pair of electrons (empty square) — in their shell of valence electrons.R represents any group that can donate a single atom for ...

The atoms of other elements, however, like hydrogen, join with another hydrogen atom as a pair, making a molecule. So, all compounds are molecules, and some elements are too. Back to top ...