Higher Advanced Chemistry SQA

Electromagnetic Radiation

Section 1: Introduction and Nature of Electromagnetic Radiation

• Electromagnetic radiation refers to the form of energy propagated in the form of electromagnetic waves, including light.
• These radiations range from long radio waves to short gamma rays and are characterised by the electromagnetic spectrum.
• Each radiation possesses two field components - electric and magnetic, perpendicular to each other and to the direction of propagation.
• Spectral regions are assigned specific names such as UV, visible, infrared, among others, based on their wavelengths.
• These radiations exhibit both particle-like and wave-like behaviour, which is known as wave-particle duality.

Section 2: Properties of Electromagnetic Radiations

• All electromagnetic radiations move at the speed of light in the vacuum, approximately 3.00 x 10^8 m/s.
• These waves possess different energies and frequencies but differ in wavelengths.
• They can transmit energy, travel in a straight line and have the power to penetrate various types of materials.
• They can also be reflected, refracted and diffracted, similar to the manner in which light behaves.

Section 3: Applications in Inorganic Chemistry

• Spectroscopy, a crucial technique in chemistry, deeply relies on the study of interaction between matter and electromagnetic radiation.
• Electron configuration in atoms can be described using the spectral lines emitted or absorbed by them.
• UV-Visible spectroscopy provides information about electronic transitions in atoms, ions, or molecules.
• IR spectrography is commonly used to determine the vibrational modes of molecules, hence, providing insight into molecular structures.
• X-ray diffraction is another technique which provides data on crystal structures of inorganic compounds, thanks to the interaction between short-wavelength x-rays and matter.