Periodic Table Pen
Keep the periodic table close at hand with the periodic table pen. Table pulls out from pen and neatly rolls back into the barrel once your curiosity is satisfied. Elements, their melting points, boiling points, and atomic masses are printed on the front. Multiple physical constants, gas law equations, and conversion factors are listed on the back. Pull out chart measures 7 × 2-1/2". Periodic table measures 4 × 2-1/2".