Cesium frequently is used in photocells because its work function (3.43 × 10(to the -19th power) j) is the lowest of all the elements. such photocells are ef cient because the broadest range of wavelengths of light can eject electrons. what colors of light will eject electrons from cesium? what colors of light will eject electrons from selenium, which has a work function of 9.5 × 10(to the -19th power) j?