Complex sentence: In 2009, sections of classes were named after elements in the Periodic table In School Year 2013-2014, sections were named after constellations, scientists, units of measurement, and molecular and atomic parts.
Split into simpler sentences: In 2009, sections of classes were named after elements in the periodic table. In 2013-2014, sections were named after constellations, scientists, units of measurement, and molecular and atomic parts.