Context: A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes may occur., Intermolecular forces (IMFs) are the forces which mediate interaction between molecules. They also include forces of attraction or repulsion which act between molecules and other types of neighboring particles (e.g., atoms or ions). They are weak compared to the intramolecular forces  the forces which keep a molecule together. For example, the covalent bond, involving the sharing of electron pairs between atoms, is much stronger than the forces present between neighboring molecules. Both sets of forces are essential parts of force fields frequently used in molecular mechanics., The Royal Swedish Academy of Sciences or "Kungliga Vetenskapsakademien" is one of the Royal Academies of Sweden. It is an independent, non-governmental scientific organisation which takes special responsibility for the natural sciences and mathematics, but endeavours to promote the exchange of ideas between various disciplines., Peace occurs between heterogeneous social groups and is characterized by a lack of conflict and freedom from fear of violence. Commonly understood as the absence of hostility, peace often involves compromise, and therefore is initiated with thoughtful listening and communication to enhance and create mutual understanding., In the classical physics observed in everyday life, if something has mass and takes up space, it is said to be composed of matter; this includes atoms (and thus molecules) and anything made up of these, but not other energy phenomena or waves such as light or sound. More generally, however, in (modern) physics, matter is not a fundamental concept because a universal definition of it is elusive: elementary constituents of atoms may not take up space individually, and massless particles may be composed to form objects that have mass (even when at rest)., Jacobus Henricus van 't Hoff, Jr. (30 August 1852  1 March 1911) was a Dutch physical chemist. A highly influential theoretical chemist of his time, van 't Hoff was the first winner of the Nobel Prize in Chemistry. His pioneering work helped found the modern theory of chemical affinity, chemical equilibrium, chemical kinetics, and chemical thermodynamics. In his 1874 pamphlet Van't Hoff formulated the theory of the tetrahedral carbon atom and laid the foundations of stereochemistry. In 1875 he predicted the correct structures of allenes and cumulenes as well as their axial chirality. He is also widely considered one of the founders of physical chemistry as the discipline is known today., In physics, a force is any interaction that, when unopposed, will change the motion of an object. In other words, a force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F., Vienna Standard Mean Ocean Water (VSMOW) is a water standard defining the isotopic composition of fresh water. It was promulgated by the International Atomic Energy Agency (based in Vienna) in 1968, and, since 1993, continues to be evaluated and studied by the IAEA along with the European Institute for Reference Materials and Measurements and the American National Institute of Standards and Technology. The standard includes both the established values of stable isotopes found in waters and calibration materials provided for standardization and interlaboratory comparisons of instruments used to measure these values in experimental materials., A chemical compound (or just compound if used in the context of chemistry) is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds. There are four types of compounds, depending on how the constituent atoms are held together: molecules held together by covalent bonds, ionic compounds held together by ionic bonds, intermetallic compounds held together by metallic bonds, and certain complexes held together by coordinate covalent bonds. Many chemical compounds have a unique numerical identifier assigned by the Chemical Abstracts Service (CAS): its CAS number., The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons), electron configurations, and recurring chemical properties. This ordering shows "periodic trends", such as elements with similar behaviour in the same column. It also shows four rectangular blocks with some approximately similar chemical properties. In general, within one row (period) the elements are metals on the left, and non-metals on the right., Deuterium (symbol ' or ', also known as heavy hydrogen) is one of two stable isotopes of hydrogen. The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common hydrogen isotope, protium, has no neutron in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom in of hydrogen. Thus deuterium accounts for approximately 0.0156% (or on a mass basis 0.0312%) of all the naturally occurring hydrogen in the oceans, while the most common isotope (hydrogen-1 or protium) accounts for more than 99.98%. The abundance of deuterium changes slightly from one kind of natural water to another (see Vienna Standard Mean Ocean Water)., An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are very small; typical sizes are around 100 picometers (a ten-billionth of a meter, in the short scale)., Physics (from , from "phúsis" "nature") is the natural science that involves the study of matter and its motion and behavior through space and time, along with related concepts such as energy and force. One of the most fundamental scientific disciplines, the main goal of physics is to understand how the universe behaves., Medicine (British English ; American English ) is the science and practice of the diagnosis, treatment, and prevention of disease. The word "medicine" is derived from Latin "medicus", meaning "a physician". Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Contemporary medicine applies biomedical sciences, biomedical research, genetics, and medical technology to diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, external splints and traction, medical devices, biologics, and ionizing radiation, amongst others., Isotopes are variants of a particular chemical element which differ in neutron number. All isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos ( "equal") and topos ( "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table., The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine. This award is administered by the Nobel Foundation and awarded by Royal Swedish Academy of Sciences on proposal of the Nobel Committee for Chemistry which consists of five members elected by Academy. The award is presented in Stockholm at an annual ceremony on December 10, the anniversary of Nobel's death. The first Nobel Prize in Chemistry was awarded in 1901 to Jacobus Henricus van 't Hoff, of the Netherlands, "for his discovery of the laws of chemical dynamics and osmotic pressure in solutions.", Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry includes topics such as the properties of individual atoms, how atoms form chemical bonds to create chemical compounds, the interactions of substances through intermolecular forces that give matter its general properties, and the interactions between substances through chemical reactions to form different substances., Literature, in its broadest sense, is any single body of written works. More restrictively, it is writing considered as an art form, or any single writing deemed to have artistic or intellectual value, often due to deploying language in ways that differ from ordinary usage. Its Latin root "literatura"/"litteratura" (derived itself from "littera": "letter" or "handwriting") was used to refer to all written accounts, though contemporary definitions extend the term to include texts that are spoken or sung (oral literature). Literature can be classified according to whether it is fiction or non-fiction and whether it is poetry or prose; it can be further distinguished according to major forms such as the novel, short story or drama; and works are often categorized according to historical periods or their adherence to certain aesthetic features or expectations (genre)., Harold Clayton Urey ( April 29 , 1893 -- January 5 , 1981 ) was an American physical chemist whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934 for the discovery of deuterium . He played a significant role in the development of the atom bomb , but may be most prominent for his contribution to theories on the development of organic life from non-living matter . Born in Walkerton , Indiana , Urey studied thermodynamics under Gilbert N. Lewis at the University of California . After he received his PhD in 1923 , he was awarded a fellowship by the American - Scandinavian Foundation to study at the Niels Bohr Institute in Copenhagen . He was a research associate at Johns Hopkins University before becoming an associate professor of Chemistry at Columbia University . In 1931 , he began work with the separation of isotopes that resulted in the discovery of deuterium . During World War II Urey turned his knowledge of isotope separation to the problem of uranium enrichment . He headed the group located at Columbia University that developed isotope separation using gaseous diffusion . The method was successfully developed , becoming the sole method used in the early post-war period . After the war , Urey became professor of chemistry at the Institute for Nuclear Studies , and later Ryerson professor of chemistry at the University of Chicago . Urey speculated that the early terrestrial atmosphere was probably composed of ammonia , methane , and hydrogen . One of his Chicago graduate students was Stanley L. Miller , who showed in the Miller -- Urey experiment that , if such a mixture be exposed to electric sparks and water , it can interact to produce amino acids , commonly considered the building blocks of life . Work with isotopes of oxygen led to pioneering the new field of paleoclimatic research . In 1958 , he accepted a post as a professor at large at the new University of California , San Diego ( UCSD ) , where he helped create the science faculty . He was one of the founding members of UCSD 's school of chemistry , which was created in 1960 . He became increasingly interested in space science , and when Apollo 11 returned moon rock samples from the moon , Urey examined them at the Lunar Receiving Laboratory ., The Nobel Committee for Chemistry is the Nobel Committee responsible for proposing laureates for the Nobel Prize in Chemistry. The Nobel Committee for Chemistry is appointed by the Royal Swedish Academy of Sciences. It usually consists of Swedish professors of chemistry who are members of the Academy, although the Academy in principle could appoint anyone to the Committee., Structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as biological organisms, minerals and chemicals. Abstract structures include data structures in computer science and musical form. Types of structure include a hierarchy (a cascade of one-to-many relationships), a network featuring many-to-many links, or a lattice featuring connections between components that are neighbors in space., The Swedish Academy, founded in 1786 by King Gustav III, is one of the Royal Academies of Sweden. It is known for making the annual decision on who will be the laureate for the Nobel Prize in Literature, awarded in memory of the donor Alfred Nobel., The neutron is a subatomic particle, symbol or , with no net electric charge and a mass slightly larger than that of a proton. Protons and neutrons, each with mass approximately one atomic mass unit, constitute the nucleus of an atom, and they are collectively referred to as nucleons. Their properties and interactions are described by nuclear physics., Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane. It is also defined as the measure of the tendency of a solution to take in water by osmosis. Potential osmotic pressure is the maximum osmotic pressure that could develop in a solution if it were separated from distilled water by a selectively permeable membrane. The phenomenon of osmosis arises from the propensity of a pure solvent to move through a semi-permeable membrane and into a solution containing a solute to which the membrane is impermeable. This process is of vital importance in biology as the cell's membrane is semipermeable., In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomic weight listed for the element in the periodic table. The abundance of an isotope varies from planet to planet, and even from place to place on the Earth, but remains relatively constant in time (on a short-term scale)., Physiology is the scientific study of the normal function in living systems. A sub-discipline of biology, its focus is in how organisms, organ systems, organs, cells, and biomolecules carry out the chemical or physical functions that exist in a living system. Given the size of the field, it is divided into, among others, animal physiology (including that of humans), plant physiology, cellular physiology, microbial physiology (microbial metabolism), bacterial physiology, and viral physiology. The Nobel Prize in Physiology or Medicine is awarded to those who make significant achievements in this discipline by the Royal Swedish Academy of Sciences. In medicine, a physiologic state is one occurring from normal body function, rather than pathologically, which is centered on the abnormalities that occur in animal diseases, including humans., Alfred Bernhard Nobel (21 October 1833  10 December 1896) was a Swedish chemist, engineer, inventor, businessman, and philanthropist., Subject: harold urey, Relation: field_of_work, Options: (A) arrangement (B) art (C) biology (D) chemist (E) chemistry (F) gas (G) health care (H) language (I) literature (J) mathematics (K) mechanics (L) medicine (M) musical (N) nature (O) novel (P) peace (Q) physical chemistry (R) physician (S) physics (T) physiology (U) plant (V) plant physiology (W) poetry (X) research (Y) science (Z) short story ([) surgery (\) technology (]) thermodynamics
Output: physical chemistry