Inorganic Chemistry: Electromagnetic Radiation

Inorganic Chemistry: Electromagnetic Radiation

Properties of Electromagnetic Radiation

  • Electromagnetic radiation is a form of energy that travels in waves and does not require a medium.
  • It travels at a constant speed of 3 x 10^8 metres per second in a vacuum.
  • The wavelength (distance between two consecutive peaks) and frequency (number of waves passing a point per unit time) are key properties.
  • There is an inverse relationship between frequency and wavelength: as one increases, the other decreases.

Different Types of Electromagnetic Radiation

  • Electromagnetic radiation spans a broad range, known as the electromagnetic spectrum.
  • The spectrum is divided into different types: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
  • The energy of electromagnetic radiation increases from radio waves to gamma rays.

Electromagnetic Radiation and Atoms

  • Atoms can absorb certain frequencies of electromagnetic radiation, causing electrons to move to higher energy levels.
  • When the excited electrons return to lower energy levels, atoms emit electromagnetic radiation at the same frequency as the absorbed radiation.
  • This process is fundamental to spectroscopic techniques such as atomic absorption spectroscopy.

Importance of Electromagnetic Radiation

  • Chemical bonds absorb and emit specific frequencies of electromagnetic radiation, giving each element and compound a unique spectral “fingerprint”.
  • This allows identification and analysis of unknown substances in fields ranging from forensic science to space exploration.

Health Implications of Electromagnetic Radiation

  • Some forms of electromagnetic radiation, such as gamma rays and X-rays, carry enough energy to remove tightly held electrons from atoms, creating ions.
  • This ionising radiation can damage cells and DNA, leading to health problems like cancer.
  • Other types, such as visible light and radio waves, are considered non-ionising and generally less harmful.

Safety Measures

  • To prevent harmful exposure, shields (for ionising radiation) or distance (for non-ionising radiation) are employed.
  • Safety regulations and guidelines are implemented to limit public and occupational exposure.