High school biology teacher Kelly Chavis knew smartphones were a problem in her class. But not even the students realized how much of a problem the devices were until Chavis did an in-class experiment. For one class period, students used a whiteboard to count every Snapchat, Instagram, text, call or other notification that appeared on their phones. Chavis told students to not respond to these notifications. Teachers around the country have done similar experiments, usually recording dozens of markings on the whiteboard. Chavis, who teaches honors-level classes at Rock Hill Schools in South Carolina, was shocked by the results of her experiment. “One girl, just during the one hour, got close to 150 Snapchat notifications...150!” she said. Chavis is among a growing number of teachers, parents and health experts who believe that smartphones are now partly to blame for increasing the levels of student anxiety. The use of electronic devices is so widespread that the National Education Association newsletter said it was a ”mental health tsunami.