An electron is ejected from a metal with a velocity 6.70 x 105 m/s. If the metal has a threshold frequency of 1.50 x 1015 Hz, what was the wavelength of the incident

photon?

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume