The minimum energy required to cause an electron to be emitted from a clean zinc surface is 6.9 x 10^-19. (a) Calculate the maximum wavelength of electromagnetic radiation which will cause an electron to be emitted from the clean zinc surface.
(b)What would be the effect of irradiating a clean zinc surface with radition of wavelength 4.0x 10^-7? You must justify your answer.

What layer of the atmosphere is directly above the troposphere?

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Asap! will give brainiest when a heat wave strikes a region causing more people to run air-conditioning units, electrical demand increases. what needs to be done to meet this increased demand? raising the control rodslowering the control rodsremoving the control rods