Einstein Mcfly said:By "threshold frequency" do you mean "work function" as in photoelectric effect? In that case, it's the ionization energy/electron affinity/all that stuff based on the "physical property" of charge shielding etc.
Physical properties are characteristics of a substance that can be observed or measured without causing any chemical changes. These properties include characteristics such as mass, volume, density, color, and state of matter.
Physical properties are different from chemical properties because they do not involve any changes in the chemical composition of a substance. Chemical properties, on the other hand, describe how a substance reacts with other substances and can result in a change in its chemical composition.
Understanding physical properties is important in many fields of science, as it allows scientists to identify and classify different substances, predict how they will behave under certain conditions, and develop new materials and technologies.
Threshold frequency is the minimum frequency of light that is needed to cause the ejection of an electron from a metal surface. This phenomenon, known as the photoelectric effect, was discovered by Albert Einstein and is an important concept in quantum mechanics.
The higher the frequency of light above the threshold frequency, the greater the energy of the ejected electrons. However, increasing the intensity of the light has no effect on the kinetic energy of the ejected electrons. This is a key principle of the photoelectric effect and helped scientists better understand the nature of light and matter.