Images © Murray Robertson 1999-2011 Text © The Royal Society of Chemistry 1999-2011 Welcome to "A Visual Interpretation of The Table of Elements", the most striking version of the periodic table on the web. This Site has been carefully prepared for your visit, and we ask you to honour and agree to the following terms and conditions when using this Site.

Electronegativity (Pauling scale)The tendency of an atom to attract electrons towards itself, expressed on a relative scale.

Period A horizontal row in the periodic table. The atomic number of each element increases by one, reading from left to right.

The material will not be the same for etching as for line engraving. The following list will provide you with some basic references so that you can make your first purchases with an easy mind. Don't hesitate to choose good quality tools, even for first use!

If you wish to use the Images in a manner not permitted by these terms and conditions please contact the Publishing Services Department by email. If you are in any doubt, please ask.

An integrated supply risk index from 1 (very low risk) to 10 (very high risk). This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores.

A measure of the stiffness of a substance. It provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain.

A measure of the propensity of a substance to evaporate. It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system.

The oxidation state of an atom is a measure of the degree of oxidation of an atom. It is defined as being the charge that an atom would have if all bonds were ionic. Uncombined elements have an oxidation state of 0. The sum of the oxidation states within a compound or ion must equal the overall charge.

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Varnish for etching Varnishes are used in etching to protect the plate from biting. These varnishes have a bitumen and wax base that is diluted in oil. Varnishes of varying quality are available, and the type of varnish chosen will depend on what it is being used for. Make sure you have one or two flat synthetic brushes and some finer brushes to apply the varnish on the plate. Available varnishes:

Block Elements are organised into blocks by the orbital type in which the outer electrons are found. These blocks are named for the characteristic spectra they produce: sharp (s), principal (p), diffuse (d), and fundamental (f).

CAS number The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems.

Allotropes Some elements exist in several different structural forms, called allotropes. Each allotrope has different physical properties.

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Covalent radiusHalf of the distance between two atoms within a single covalent bond. Values are given for typical oxidation number and coordination.

The availability of suitable substitutes for a given commodity. High = substitution not possible or very difficult. Medium = substitution is possible but there may be an economic and/or performance impact Low = substitution is possible with little or no economic and/or performance impact

Atomic radius, non-bonded Half of the distance between two unbonded atoms of the same element when the electrostatic forces are balanced. These values were determined using several different methods.

A measure of how difficult it is to deform a material. It is given by the ratio of the shear stress to the shear strain.

Copyright of and ownership in the Images reside with Murray Robertson. The RSC has been granted the sole and exclusive right and licence to produce, publish and further license the Images.

The RSC makes no representations whatsoever about the suitability of the information contained in the documents and related graphics published on this Site for any purpose. All such documents and related graphics are provided "as is" without any representation or endorsement made and warranty of any kind, whether expressed or implied, including but not limited to the implied warranties of fitness for a particular purpose, non-infringement, compatibility, security and accuracy.

A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators.

Group A vertical column in the periodic table. Members of a group typically have similar properties and electron configurations in their outer shell.

The percentage of the world reserves located in the country with the largest reserves. The higher the value, the larger risk there is to supply.

Commercial use of the Images will be charged at a rate based on the particular use, prices on application. In such cases we would ask you to sign a Visual Elements licence agreement, tailored to the specific use you propose.

The oldest presses, in cast iron, are very effective but their heavy weight means they are difficult to move. Steel presses are just as effective.

A measure of how difficult it is to compress a substance. It is given by the ratio of the pressure on a body to the fractional decrease in volume.

Relative atomic mass The mass of an atom relative to that of carbon-12. This is approximately the sum of the number of protons and neutrons in the nucleus. Where more than one isotope exists, the value given is the abundance weighted average.

A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators.

Murray Robertson is the artist behind the images which make up Visual Elements. This is where the artist explains his interpretation of the element and the science behind the picture.

Sublimation The transition of a substance directly from the solid to the gas phase without passing through a liquid phase.

The percentage of an element produced in the top producing country. The higher the value, the larger risk there is to supply.