The Law of Conservation of Mass states that mass cannot be created or destroyed. The object can be rearranged in space and changed into different particles.
The following is an example of an experiment showing that Iron (Fe) and Sulfur (Su), after being weighed and heated, has the same amount of chemical mass before the chemical reaction as it did after the chemical reaction resulting in the compound Iron 2 Sulfide. http://www.yteach.co.uk/page.php/resources/view_all?id=atom_atomic_mass_molecular_equation_calculation_relative_compound_page_0&from=search {please note you will have to "x" out of the demonstration page which covers the picture.}
The scientist Dr. Janet Conrad has a few words to explain The Law of Conservation of Mass resulting in the equation, E=mc2, (squared). Check this site out: http://www.pbs.org/wgbh/nova/einstein/expe-conrad.html.
The scientist Dr. Michio Kaku explains why energy and mass are the same or equal to each other. He also explains how he got interested in the atom. http://www.pbs.org/wgbh/nova/einstein/expe-kaku.html
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Let's look under those beds for our socks. The socks are not destroyed!