字幕列表 影片播放 列印英文字幕 Most of us think of light as a wave. Waves easily explain interactions such as reflection. However, early in the 20th century, some scientists noticed that light hitting a metal surface can sometimes eject electrons. How can light waves do this? Albert Einstein showed this can only happen if light is made up of tiny particles called photons. Einstein revolutionized physics by describing light as photons. Scientists now believe light exhibits both wave and particle properties. To access a comprehensive array of complete multimedia lessons, as well as the most up-to-date, standards-based curriculum content that's researched, proven and teacher-approved, visit newpathlearning.com to create your FREE online learning account now! Each multimedia lesson includes animated presentations interactive activities, virtual labs, vocabulary exercises and standards-based assessments.