"It is only the absorbed light radiations that are effective in producing a chemical reactions." This is the statement of (a) Lambert law (b) Lambert-Beer law (c) Grotthus-Draper law (d) Stark-Einstein law

Firstly, evaluate the statement, 'It is only the absorbed light radiations that are effective in producing chemical reactions.' This statement suggests that for a chemical reaction to occur, light radiation must be absorbed. This is a fundamental concept of one particular law in physics and chemistry, which states that only absorbed light can cause a chemical reaction.

Secondly, compare the statement to each law: \n- Lambert law is related to the intensity of light falling upon a surface decreasing exponentially with the thickness of the absorbed material, which does not align with our statement. \n- Lambert-Beer law describes how the absorption of light by a substance is directly proportional to its concentration, which again is not closely related to our statement. \n- Grotthus-Draper law, also known as the Principle of Photochemical Activation, states exactly this concept: that only the light that is absorbed by a system can bring about a photochemical change. \n- Stark-Einstein law is about the photon emission and absorption processes, which is not directly related to the statement.

After comparing the options, it is clear that the statement aligns most closely with Grotthus-Draper law. Therefore, the correct answer is Grotthus-Draper law.