This website contains some items copyrighted by Keith Enevoldsen (author/artist). These items are marked with a copyright notice. Specifically, "The Periodic Table of the Elements, in Pictures" and "The Periodic Table of the Elements, in Words" and other PDF files (for high-quality prints and posters) are copyrighted.

Other items, such as most of the regular HTML pages (not PDF files), are not marked with copyright notices. You may copy these non-copyrighted items, or even modify them, with or without attribution.

The copyrighted items have the following terms of use.

Terms of Use:

• You MAY print or photocopy these copyrighted items (ex., PDF posters/charts) for your personal use or for LIMITED distribution (up to 100 per year for your students, friends, or family) free of charge. However, donations are appreciated (see Donate). Also, products are available for sale (see Buy Products).
  
  
• You MAY make links to this website, elements.wlonk.com, from other websites, provided that you link to the HTML page rather than linking directly to the individual items (ex., the PDF files). Linking to the HTML page ensures that visitors are able to access links to the full and current Terms of Use.
  
  
• You MAY NOT modify these copyrighted items (ex., PDF posters/charts). Do not add, change, or remove content. Do not remove the copyright notice or web address. When printing or displaying these copyrighted items, other text or graphics, especially company logos, must be very clearly separated from the copyrighted item, preferably on a separate page, to avoid any appearance that another company or entity owns the copyrighted content.
  
  
• You MAY NOT distribute digital copies of these copyrighted items (ex., PDF posters/charts), nor copy them to another website, without my explicit written permission in the form of a contract (see contact info below).
  
  
• You MAY NOT distribute hard copies of these copyrighted items (ex., PDF posters/charts) widely (to the general public or to more than 100 per year of your students, friends, or family), without my explicit written permission (see contact info below).
  
  
• You MAY NOT sell digital copies nor hard copies of these copyrighted items (ex., PDF posters/charts) without my explicit written permission in the form of a contract (see contact info below).