2) For the BOD measurement routine, 3 mL of a wastewater was added to a BOD bottle (300 ml) and
the clean water was added to fill up the bottle. The
dissolved oxygen DO was measured in this bottle as
9.4 mg/L and then the bottle was incubated for 5
days. The DO measured after 5 days was 2.3 mg/L.
The BOD of the wastewater (in mg/L) was (rounded to
1 decimal place).
2points​

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.