Definition of ionize in English:


(also ionise)


  • 1Convert (an atom, molecule, or substance) into an ion or ions, typically by removing one or more electrons.

    • ‘The reactant ions have enough energy to ionise the molecules of interest but not enough to break them up.’
    • ‘Once removed from an atom, an electron may in turn ionize other atoms or molecules.’
    • ‘Radioactive elements in the sample or in the surrounding environment ionize the atoms in crystalline quartz, and the electrons become trapped by crystal defects.’
    • ‘As the ion beam hits a small patch of the sample surface, it desorbs and ionizes the atoms in its path.’
    • ‘A single free electron traveling in a strong, uniform electric field ionizes the gaseous molecules around it, generating more electrons and a chain reaction of ionization.’
    • ‘When the charged particles of the solar wind hit the atmosphere, various gases present in the atmosphere heat up, split apart molecules, and ionize atoms.’
    • ‘When a photoelectron strikes a hole, it ionizes atoms at the point of impact.’
    • ‘A narrow beam of laser light gradually spreads out due to wave diffraction, and if it's ionizing some substance, it will gradually lose its intensity.’
    • ‘When a photon strikes the PV cell it ionises a silicon atom, transferring all its energy to an outer electron and allowing that electron to break free from the silicon atom.’
    • ‘The slower they move, the more efficient they are at ionizing atoms in their path and the more likely they are to interact with atomic nuclei.’
    • ‘Other detectors depend on the electrons from a decay to ionize other atoms and produce an electric current proportional to the decay energy.’
    • ‘Making hydrogen atoms transparent to light involves a similar but much more energetic event: beams of energy must ionize the atoms, splitting them into protons and electrons.’
    • ‘Astronomers propose that a group of ancient, massive stars ended the so-called cosmic Dark Ages by ionizing hydrogen and helium atoms, lighting up the universe for the first time since the Big Bang.’
    • ‘The alpha particles emitted by the radioactive decay of the americium - 241 ionize the oxygen and nitrogen atoms present in the chamber, giving rise to free electrons and ions.’
    • ‘Solar protons pose the biggest threat to us because they ionise molecules along their tracks.’
    • ‘These are positioned on either side of the heat sink wall, and switching on the voltage causes a transfer of electrons which positively ionise the air molecules.’
    • ‘In fairness, any radiation that can ionize an atom can affect chemical changes in a substance.’
    • ‘The complete spectrum of radiation from the sun contains a significant amount of high energy ultraviolet light and the energy of these photons is sufficient to ionize atoms or molecules.’
    • ‘Previous research has shown that a sudden extreme temperature change ionizes reagents and elevates electrons into excited energy states, producing an electromagnetic pulse.’
    • ‘They then bombarded the condensate with low-energy electrons like those created by cosmic rays ionizing atoms in the atmosphere.’
    1. 1.1no object Become converted into an ion or ions; undergo ionization.
      • ‘Evidently, any disruption of the HB-net between Glu - 222 and Tyr - 66 should eliminate the Cro reprotonation in the GS, which would then remain permanently ionized.’
      • ‘But despite frequent theorizing to the contrary, the lower-frequency beams don't ionize; they pack just enough punch to penetrate and reflect but not to separate electrons from atoms entirely.’
      • ‘This means that the dirt allows the air to become ionized more easily.’
      • ‘Although the universe was no longer hot or ionized, it was still dark.’
      • ‘Plasmas are forms of matter in which a significant fraction of the neutral atoms and molecules have been ionized to form free electrons and ions.’
      • ‘The phosphate leaves the protein near pH 4, slightly lower than where Glu - 58 becomes ionized.’
      • ‘When dust and gas fall into a black hole, they can be sucked towards the event horizon so fast that the atoms are ionized and release bright light that escapes without crossing the event horizon.’
      • ‘It takes different conformations when it is neutral and ionized.’
      • ‘Bursts that occur later, after hydrogen has ionized, don't have such a gap.’
      • ‘The state develops when a gas is heated to such a high temperature that all atoms in the gas are ionized.’
      • ‘The key point is that strong means 100% ionised.’
      • ‘The gas molecules are then ionized, that is, converted into electrically charged fragments.’
      • ‘The atoms become ionized by the sun's ultraviolet radiation and are then accelerated to enormous energies by the solar wind.’
      • ‘When light shines on certain negative metallic electodes in a vacuum, the metal is ionized and cathode rays, i.e. electrons, are emitted.’
      • ‘In a neutral atom, the number of electrons is the same as the number of protons but atoms can be ionized, either oxidized or reduced, and end up with a different electron count.’
      • ‘Nitric acid is completely ionized in solution and as such it is a strong acid and an efficient oxidizing reagent.’
      • ‘So the physicists turned back the clock and imagined an epoch when the universe was so hot that all its atoms were completely ionized - when all atomic nuclei were laid bare and all electrons roamed free.’
      • ‘The gas atoms are ionized, and the liberated electrons are then driven back to the parent atom by the light field and emit light at frequencies that are multiples of the original laser frequency.’
      • ‘The absorption of calcium is dependent on its becoming ionized in the intestines.’
      • ‘Atoms are ionised and desorb from the sample surface ready for MS analysis.’