Current Events

  • Atmospheric CO2 Level Tops 400 ppm
    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm rep...Read more

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    Atmospheric CO2 Level Tops 400 ppm

    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.
  • Massive Tornado Outbreak on Tornado Alley
    The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Io...Read more

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    Massive Tornado Outbreak on Tornado Alley

    The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Iowa, Illinois and Missouri. On May 20th, a massive tornado struck Moore, Oklahoma, devastating communities - destroying over 100 homes and hitting two elementary schools and a hospital - with many casualties and deaths. Our thoughts are with our friends and colleagues suffering from these storms. For more on the May 20th storms, see the NOAA Storm Prediction Center Storm Report.
  • Kansas Legislator Proposes Bill to Outlaw Sustainability Education
    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of ...Read more

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    Kansas Legislator Proposes Bill to Outlaw Sustainability Education

    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of sustainability. Here is a link to the one-page bill: http://www.kslegislature.org/li/b2013_14/measures/documents/hb2366_00_0000.pdf. See report on Bloomberg News.
Water as a liquid, solid and gas.
Click on image for full size
L.Gardiner/Windows to the Universe

Changes of State: Solids, Liquids, and Gases

Any substance, called matter, can exist as a solid material, liquid, or gas. These three different forms are called states. Matter can change its state when heated.

As a solid, matter has a fixed volume and shape and is usually unable to flow, except in the case of glaciers. For instance, an ice cube or snowflake is the solid state of water.

When the solid state of matter is heated, it turns into a liquid. As a liquid, a substance has a fixed volume, but its shape changes to fill the shape of its container. For instance, a glass of water is the liquid state of water.

When the liquid state of matter is heated, it turns into a gas. As a gas, a substance does not have a fixed volume or shape. Gas expands to fill the shape and volume of its container. For instance, the steam that comes out of a hot teakettle, making the whistle blow, is water as a gas.

Heat causes matter to change its state because, when heated, the molecules within the substance to move around faster. The faster the molecules bounce about, the weaker they are held together.

Last modified May 10, 2010 by Randy Russell.

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