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Atmospheric Chemistry

Periodic Graphics

Periodic Graphics: The chemistry of snow and ice

Chemical educator and Compound Interest blogger Andy Brunning explores water’s unique behavior when temperatures plummet

by Andy Brunning
January 26, 2020 | A version of this story appeared in Volume 98, Issue 4


Andy Brunning/C&EN
Andy Brunning/C&EN

To download a PDF of this article, visit:

References used to create this graphic:

Brunning, Andy. “The Shapes of Snowflakes.” Compound Interest, Dec. 10, 2014.

Conners, Deanna. “How Snowflakes Get Their Shapes.” EarthSky, Jan. 28, 2019.

Lemonick, Sam. “Scientists Find the Smallest Number of Water Molecules That Can Form Ice.” Chemical & Engineering News, Nov. 7, 2019.

McNeill, V. Faye, and Meredith G. Hastings. “Ice in the Environment: Connections to Atmospheric Chemistry.” Environ. Res. Lett. (2008). DOI: 10.1088/1748-9326/3/4/045004.

A collaboration between C&EN and Andy Brunning, author of the popular graphics blog Compound Interest

To see more of Brunning’s work, go to To see all of C&EN’s Periodic Graphics, visit



This graphic was updated on Feb. 11, 2020, to clarify the plot of density versus temperature for water and ice. Originally, the plot depicted density versus temperature for liquid water at all temperatures. To better match the text in the graphic, the plot has been updated to depict density versus temperature for liquid water above 0 °C and for ice below 0 °C.

This graphic's references were updated also on Feb. 11, 2020, to add in missing entries and correct the spelling of Deanna Conners's name.


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