how does a light spectrophotometer work?

Question

what happens to the molecule when they are effected by the light, how do they get to that particular wavelenght is ther some sort of electomagnetic radient energy that effects the molecule, if so what happens to them.

Answer 1

n physics, spectrophotometry is the quantitative study of electromagnetic spectra. It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light, near-ultraviolet, and near-infrared. Also, the term does not cover time-resolved spectroscopic techniques.

Spectrophotometry involves the use of a spectrophotometer. A spectrophotometer is a photometer (a device for measuring light intensity) that can measure intensity as a function of the color, or more specifically, the wavelength of light. There are many kinds of spectrophotometers. Among the most important distinctions used to classify them are the wavelengths they work with, the measurement techniques they use, how they acquire a spectrum, and the sources of intensity variation they are designed to measure. Other important features of sp

Answer 2

Don't confuse the atomic interactions with light at the source with what is going on in the spectrophotometer. The instrument contains a diffraction grating, typically a piece of glass or plastic ruled with fine lines very close together. If light strikes the grating at an angle, it may happen that the distance beween rulings (as seen by the light wave) will be exactly one wavelength, and in such case that wavelength will be preferentially reflected. This generates a spectrum, which can fall on a scale or be recorded photographically or electronically. Emission lines from the source can be seen as distinct lines on the spectrophotometer scale.

Answer 3

The molecule absorbs the photon, bouncing an electron up to a higher energy level. The frequency of the light that is absorbed is the energy difference between the orbital where the electron was initially and where it ended up. This creates an electronically excited molecule, that will relax back to the ground state with the production of heat, ready to absorb another photon.

Answer 4

Some photons in light are absorbed by the electrons in the molecules, and some are bounced back or pass through depending on the properties of the molecules and the temperature, etc etc. It's really complex subatomic physics.