What does a plateau represent on hearing curve

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.

How does kepler second law of planetary motion overthrow one of the basic beliefs of classical astronomy

Rank the following four acids in order of increasing bronsted acidity : h2f+ , ch3oh, (ch3)2oh+ , ch3sh2+