This document discusses instrumental analytical techniques, specifically spectroscopy. It defines spectroscopy as the study of the interaction of electromagnetic radiation with matter. This interaction occurs through quanta, or discrete amounts of energy absorbed or emitted by matter. The main practice in spectroscopy is measuring the frequency of radiation absorbed or emitted. It also provides background on electromagnetic radiation, defining it as a form of energy that propagates as a transverse wave through space at enormous velocity. Key wave properties like wavelength and frequency are defined.

1. Instrumental Analytical
Techniques
Spectroscopy

2.  Spectroscopy
It is branch of science dealing with the study of
interaction of electromagnetic radiation with matter.
such Interaction occurs due to energy that may be
absorbed or emitted by the matter in discrete
amounts.
Quanta- The energy absorbed or emitted by the
matter in discrete amounts called as Quanta.

3. This is main practice of spectroscopy -
Radiation frequency (emitted/absorbed) measured.
Before going to Spectroscopy –
concept of Radiation in Analytical language called as
– electromagnetic radiation.

4. Electromagnetic Radiation
It is form of energy that is transmitted through space at on
enormous velocity.
Characteristics :
1) It not requires supporting media. It more readily pass from
vaccum than in the presence of air eg. Light.
as, sound waves required air as supporting media.
2) It have the dual nature of wave and particle properties.
Wave properties: mostly includes the phenomenon like
reflection and refraction.
Particle properties: particle- photon-energy.

5. Nature of Electromagnetic Radiation
It is form of radiant energy that is transmitted through space at
on enormous velocity and propagated as a Transverse Wave.
Transverse Wave: it vibrates perpendicular to the direction of
propagation and this impart the wave motion to the light

6. The velocity of EMW: in vaccum is independent of frequency
Value: 3X108m/sec

7. Wave properties:
1) Wavelength: λ
“distance of one complete cycle/distance between two
successive maxima on electromagnetic wave// distance
between one crest to another.
Measured in units: meters- m
Centimeters-cm
milimeters-mm
micrometer- μm
nanometer-nm/ milimicrons- mμ
Aangstrom A0

8. 1) If beam having radiation from one discrete wavelength :
mono-chromatic light/source.
2) If beam having radiation of several wavelength :
Polychromatic/ Heterochromatic.
2] Frequency: ν (nu-Greek letter)
Number of cycles passing through a fixed point/ unit time orr//
Number of λ units passing through a given point in unit time.
Units: Hertz/ Fresnel
Cycles/Sec
Kilocycle/Sec [K cps or K Hz]
Megacycle/Sec [M cps or M Hz]

9. 𝜆𝜈 = 𝑐 𝑛
The wavelength and frequency are related to velocity of light.
C= velocity of light in vaccum-2.99x1010cm/sec
n= Refractive index for
light velocity in -vaccum/ study medium
n= is uniform
𝜆 =
𝐶
𝜈
3] wave number :𝜈
Reciprocal of wave length // number of waves in a unit length.
Measured by: cm-1 but used for IR.
𝜈 = 1
𝜆

10. Particle properties:
Photon/ quanta
“light shows photo-electric effect.
So assumed that electromagnetic radiation contain packets of
pure energy called as photon/quanta.
 Have energy & travel in direction of propagation of
radiation with velocity equal to light.
𝐸 = ℎ𝑣 E- energy of photon in ergs
v- Frequency in cycles/sec
h- planks’s constant 6.624x10-34joule/sec
Shorter the wavelength : greater the energy

11. Electromagnetic Spectrum

12. 1) γ rays: shorted wave
2) x rays: emitted or absorbed by movement of
electron close to nuclei.
3) UV rays:

13. Regions of the Electromagnetic
Spectrum