Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with light. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. Ionization can occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected.

1. Process of Ionization
Presenting By :-
1. Ankkit Ghag
2. Hritika Ghosalkar
3. Aakanksha Ghadi
4. Vidhit Chotaliya
5. Sanket
Muchhala Polytechnic
1St Year EJ

2. Table Of Content
1) Introduction
2) Uses
3) Production of ions
4) Ionization energy of atoms
5) Semi-classical description of ionization
6) Quantum mechanical description of ionization
7) Dissociation – distinction

3. Introduction
Ionization is the process by which an atom or
a molecule acquires a negative or positive charge by gaining
or losing electrons to form ions, often in conjunction with
other chemical changes. Ionization can result from the loss
of an electron after collisions with subatomic particles,
collisions with other atoms, molecules and ions, or through
the interaction with light. Heterolytic bond cleavage and
heterolytic substitution reactions can result in the formation
of ion pairs. Ionization can occur through radioactive decay
by the internal conversion process, in which an excited
nucleus transfers its energy to one of the inner-shell
electrons causing it to be ejected.

4. Uses
Uses :-
Everyday examples of gas ionization are such as within a fluorescent
lamp or other electrical discharge lamps. It is also used in radiation
detectors such as the Geiger-Müller counter or the ionization chamber.
The ionization process is widely used in a variety of equipment in
fundamental science (e.g., mass spectrometry) and in industry
(e.g., radiation therapy).

5. Production of ions
Negatively charged ions are produced
when a free electron collides with an
atom and is subsequently trapped
inside the electric potential barrier,
releasing any excess energy. The
process is known as electron capture
ionization.
Positively charged ions are produced by
transferring a sufficient amount of
energy to a bound electron in a collision
with charged particles (e.g. ions,
electrons or positrons) or with photons.
The threshold amount of the required
energy is known as ionization potential.
The study of such collisions is of
fundamental importance with regard to
the few-body problem (see article
on few-body systems), which is one of
the major unsolved problems in physics.

6. Ionization energy of atoms
The trend in the ionization energy of atoms is often used to demonstrate
the periodic behavior of atoms with respect to the atomic number, as
summarized by ordering atoms in Mendeleev's table. This is a valuable
tool for establishing and understanding the ordering of electrons
in atomic orbitals without going into the details of wave functions or the
ionization process.

7. Semi-classical description of ionization
Classical physics and the Bohr model of the atom can
qualitatively explain photoionization and collision-mediated
ionization. In these cases, during the ionization process, the
energy of the electron exceeds the energy difference of the
potential barrier it is trying to pass. The semi-classical
description, however, cannot describe tunnel ionization since
the process involves the passage of electron through a
classically forbidden potential barrier.

8. Quantum mechanical description of ionization
The interaction of atoms and
molecules with sufficiently strong laser
pulses leads to the ionization to singly
or multiply charged ions. The
ionization rate, i.e. the ionization
probability in unit time, can only be
calculated using quantum mechanics.
In general, the analytic solutions are
not available, and the approximations
required for manageable numerical
calculations do not provide accurate
enough results. However, when the
laser intensity is sufficiently high, the
detailed structure of the atom or
molecule can be ignored and analytic
solution for the ionization rate is
possible.

9. Dissociation – distinction
A substance may dissociate without necessarily producing ions. As
an example, the molecules of table sugar dissociate in water (sugar
is dissolved) but exist as intact neutral entities. Another subtle event
is the dissociation of sodium chloride (table salt) into sodium and
chlorine ions. Although it may seem as a case of ionization, in reality
the ions already exist within the crystal lattice. When salt is
dissociated, its constituent ions are simply surrounded by water
molecules and their effects are visible (e.g. the solution
becomes electrolytic). However, no transfer or displacement of
electrons occurs. Actually, the chemical synthesis of salt involves
ionization. This is a chemical reaction.

10. Thank You