Chemical physics
Encyclopedia
Chemical physics is a subdiscipline of chemistry
and physics
that investigates physicochemical phenomena using techniques from atomic and molecular physics
and condensed matter physics
; it is the branch of physics that studies chemical processes from the point of view of physics. While at the interface of physics
and chemistry
, chemical physics is distinct from physical chemistry
in that it focuses more on the characteristic elements and theories of physics. Meanwhile, physical chemistry studies the physical nature of chemistry. Nonetheless, the distinction between the two fields is vague, and workers often practice in each field during the course of their research.
of ions, free radicals, polymers, clusters, and molecule
s. Areas of study include the quantum mechanical behavior of chemical reaction
s, the process of solvation
, inter- and intra-molecular energy flow, and single entities such as quantum dots. Experimental chemical physicists use a variety of spectroscopic techniques to better understand hydrogen bonding, electron transfer
, the formation and dissolution of chemical bonds, chemical reactions, and the formation of nanoparticle
s. Theoretical chemical physicists create simulations of the molecular processes probed in these experiments to both explain results and guide future investigations. The goals of chemical physics research include understanding chemical structures and reactions at the quantum mechanical level, elucidating the structure and reactivity of gas
phase
ions and radicals, and discovering accurate approximations to make the physics of chemical phenomena computationally accessible. Chemical physicists are looking for answers to such questions as:
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
and physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
that investigates physicochemical phenomena using techniques from atomic and molecular physics
Atomic, molecular, and optical physics
Atomic, molecular, and optical physics is the study of matter-matter and light-matter interactions on the scale of single atoms or structures containing a few atoms. The three areas are grouped together because of their interrelationships, the similarity of methods used, and the commonality of the...
and condensed matter physics
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
; it is the branch of physics that studies chemical processes from the point of view of physics. While at the interface of physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, chemical physics is distinct from physical chemistry
Physical chemistry
Physical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
in that it focuses more on the characteristic elements and theories of physics. Meanwhile, physical chemistry studies the physical nature of chemistry. Nonetheless, the distinction between the two fields is vague, and workers often practice in each field during the course of their research.
What chemical physicists do
Chemical physicists commonly probe the structure and dynamicsDynamics (mechanics)
In the field of physics, the study of the causes of motion and changes in motion is dynamics. In other words the study of forces and why objects are in motion. Dynamics includes the study of the effect of torques on motion...
of ions, free radicals, polymers, clusters, and molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s. Areas of study include the quantum mechanical behavior of chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
s, the process of solvation
Solvation
Solvation, also sometimes called dissolution, is the process of attraction and association of molecules of a solvent with molecules or ions of a solute...
, inter- and intra-molecular energy flow, and single entities such as quantum dots. Experimental chemical physicists use a variety of spectroscopic techniques to better understand hydrogen bonding, electron transfer
Electron transfer
Electron transfer is the process by which an electron moves from an atom or a chemical species to another atom or chemical species...
, the formation and dissolution of chemical bonds, chemical reactions, and the formation of nanoparticle
Nanoparticle
In nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. Particles are further classified according to size : in terms of diameter, coarse particles cover a range between 10,000 and 2,500 nanometers. Fine particles are sized...
s. Theoretical chemical physicists create simulations of the molecular processes probed in these experiments to both explain results and guide future investigations. The goals of chemical physics research include understanding chemical structures and reactions at the quantum mechanical level, elucidating the structure and reactivity of gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
phase
Phase transition
A phase transition is the transformation of a thermodynamic system from one phase or state of matter to another.A phase of a thermodynamic system and the states of matter have uniform physical properties....
ions and radicals, and discovering accurate approximations to make the physics of chemical phenomena computationally accessible. Chemical physicists are looking for answers to such questions as:
- Can we experimentally test quantum mechanical predictions of the vibrations and rotations of simple molecules?
- Can we develop more accurate methods for calculating the electronic structure and properties of molecules?
- Can we understand chemical reactions from first principles?
- Why do quantum dots start blinkingFluorescence intermittencyFluorescence intermittency, or blinking, is the phenomenon of random switching between ON and OFF states of the emitter under its continuous excitation...
(in a pattern suggesting fractalFractalA fractal has been defined as "a rough or fragmented geometric shape that can be split into parts, each of which is a reduced-size copy of the whole," a property called self-similarity...
kineticsKinetics (physics)In physics and engineering, kinetics is a term for the branch of classical mechanics that is concerned with the relationship between the motion of bodies and its causes, namely forces and torques...
) after absorbing photonPhotonIn physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...
s of lightLightLight or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
? - How do chemical reactions really take place?
- What is the step-by-step process that occurs when an isolated molecule becomes solvated?
- Can we use the properties of negative ions to determine molecular structures, understand the dynamics of chemical reactions, or explain photodissociationPhotodissociationPhotodissociation, photolysis, or photodecomposition is a chemical reaction in which a chemical compound is broken down by photons. It is defined as the interaction of one or more photons with one target molecule....
? - Why does a stream of soft x-rays knock enough electronElectronThe electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
s out of the atomAtomThe atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
s in a xenonXenonXenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...
cluster to cause the cluster to explode?
Related fields
- Physical chemistryPhysical chemistryPhysical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
- Molecular dynamicsMolecular dynamicsMolecular dynamics is a computer simulation of physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a period of time, giving a view of the motion of the atoms...
- Quantum chemistryQuantum chemistryQuantum chemistry is a branch of chemistry whose primary focus is the application of quantum mechanics in physical models and experiments of chemical systems...
- Solid state physics
- SpectroscopySpectroscopySpectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
- Intermolecular forces
- Surface chemistry
- Van der Waals moleculeVan der Waals moleculeA van der Waals molecule is a stable cluster consisting of two or more molecules held together by van der Waals forces or by hydrogen bonds. The name originated in the beginning of the 1970s when stable molecular clusters were regularly observed in molecular beam microwave spectroscopy.In ...
s