Physical Sciences and Mathematics Commons^™

Comparison Of Chalk Types And Their Ghosting Effects, Felicienne Alexandre, Shoshanna Coon, Kirk Manfredi

Summer Undergraduate Research Program (SURP) Symposium

Chalkboard ghosting is a faint image on a chalkboard's surface after writing is erased. Many types of chalk leave a positive image, while the Crayola An-du-septic Anti-dust chalk leaves a negative image. To better understand what cause the ghosting effects, two different types of Crayola chalk (regular and anti-dust) were investigated. Raman spectroscopy and infrared (IR) spectroscopy were used to determine the majority material the chalk was made of, by comparison with pure substances. To identify the organic compound binders holding the chalk sticks together, pulverized chalk was immersed in 40 mL of toluene for at least 30 minutes. After …