A metal foil has a threshold frequency of 5.45 \times 10^{14} \text{ } \text{Hz}5.45×10 14 Hz. Which of the colors of visible light have enough energy to eject electrons from this metal? Select all that are correct. Red
Orange
Yellow
Green
Blue
Indigo
Violet

Green, Blue, Indigo, Violet

Explanation:

According to Einstein's equation of photoelectric effect, the kinetic energy of emitted photoelectron is the difference between the energy of the incident photon and the work function of the metal. The work function of the metal referee to the minimum energy that must be supplied in order to eject an electron from a metal surface. The energy of the incident photon must exceed the work function of the metal.

When we look at the electromagnetic spectrum, only the selected colours have frequency above the threshold frequency as shown by the image attached below.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e