Astudent wants to determine whether or not an unknown substance is a metal by testing its physical properties. which of the following properties would suggest that the substance is probably a metal?

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.