A proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and a mass less than that of a neutron. Protons and neutrons, each with masses of one atomic mass unit, are collectively referred to as "nucleons". One or more protons are present in the nucleus of every atom; the number of protons in the nucleus is the defining property of an element, is referred to as the atomic number. Since each element has a unique number of protons, each element has its own unique atomic number; the word proton is Greek for "first", this name was given to the hydrogen nucleus by Ernest Rutherford in 1920. In previous years, Rutherford had discovered that the hydrogen nucleus could be extracted from the nuclei of nitrogen by atomic collisions. Protons were therefore a candidate to be a fundamental particle, hence a building block of nitrogen and all other heavier atomic nuclei. Although protons were considered fundamental or elementary particles, in the modern Standard Model of particle physics, protons are classified as hadrons, like neutrons, the other nucleon.
Protons are composite particles composed of three valence quarks: two up quarks of charge +2/3e and one down quark of charge –1/3e. The rest masses of quarks contribute only about 1% of a proton's mass; the remainder of a proton's mass is due to quantum chromodynamics binding energy, which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together. Because protons are not fundamental particles, they possess a measurable size. In 2019, two different studies, using different techniques, have found the radius of the proton to be 0.833 fm, with an uncertainty of ±0.010 fm. At sufficiently low temperatures, free protons will bind to electrons. However, the character of such bound protons does not change, they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, until it is captured by the electron cloud of an atom; the result is a protonated atom, a chemical compound of hydrogen. In vacuum, when free electrons are present, a sufficiently slow proton may pick up a single free electron, becoming a neutral hydrogen atom, chemically a free radical.
Such "free hydrogen atoms" tend to react chemically with many other types of atoms at sufficiently low energies. When free hydrogen atoms react with each other, they form neutral hydrogen molecules, which are the most common molecular component of molecular clouds in interstellar space. Protons are composed of three valence quarks, making them baryons; the two up quarks and one down quark of a proton are held together by the strong force, mediated by gluons. A modern perspective has a proton composed of the valence quarks, the gluons, transitory pairs of sea quarks. Protons have a positive charge distribution which decays exponentially, with a mean square radius of about 0.8 fm. Protons and neutrons are both nucleons, which may be bound together by the nuclear force to form atomic nuclei; the nucleus of the most common isotope of the hydrogen atom is a lone proton. The nuclei of the heavy hydrogen isotopes deuterium and tritium contain one proton bound to one and two neutrons, respectively. All other types of atomic nuclei are composed of two or more protons and various numbers of neutrons.
The concept of a hydrogen-like particle as a constituent of other atoms was developed over a long period. As early as 1815, William Prout proposed that all atoms are composed of hydrogen atoms, based on a simplistic interpretation of early values of atomic weights, disproved when more accurate values were measured. In 1886, Eugen Goldstein discovered canal rays and showed that they were positively charged particles produced from gases. However, since particles from different gases had different values of charge-to-mass ratio, they could not be identified with a single particle, unlike the negative electrons discovered by J. J. Thomson. Wilhelm Wien in 1898 identified the hydrogen ion as particle with highest charge-to-mass ratio in ionized gases. Following the discovery of the atomic nucleus by Ernest Rutherford in 1911, Antonius van den Broek proposed that the place of each element in the periodic table is equal to its nuclear charge; this was confirmed experimentally by Henry Moseley in 1913 using X-ray spectra.
In 1917, Rutherford proved that the hydrogen nucleus is present in other nuclei, a result described as the discovery of protons. These experiments began after Rutherford had noticed that, when alpha particles were shot into air, his scintillation detectors showed the signatures of typical hydrogen nuclei as a product. After experimentation Rutherford traced the reaction to the nitrogen in air and found that when alpha particles were introduced into pure nitrogen gas, the effect was larger. In 1919 Rutherford assumed that the alpha particle knocked a proton out of nitrogen, turning it into carbon. After observing Blackett's cloud chamber images in 1925, Rutherford realized that the opposite was the case: after capture of the alpha particle, a proton is ejected, so that heavy oxygen, not carbon, is the end result i.e. Z is not decremented but incremented; this was 14N + α → 17O + p. Depending on one's perspective, either 1919 or
Maryland Route 178 is a state highway in the U. S. state of Maryland. Known as Generals Highway, the highway runs 8.06 miles from MD 450 in Parole north to Veterans Highway near Millersville. MD 178 connects Annapolis with Crownsville in central Anne Arundel County; the highway is indirectly named for George Washington, who traveled the highway in 1783 on his way to Annapolis to resign his commission in the Continental Army at the conclusion of the American Revolutionary War. MD 178 was planned as early as 1910 as part of a western route between Annapolis. However, most of the highway south of MD 3 was not built until the early 1930s; the portion south of MD 3 served as a primary segment in the western corridor connecting Baltimore–Annapolis, until the construction of Interstate 97 in the late 1980s. MD 178 begins at a four-way intersection featuring MD 450 in Parole. MD 450 heads west as Defense Highway and southeast as West Street toward an interchange with U. S. Route 50 and US 301 and Annapolis.
MD 178 heads north as a four-lane road with a center left-turn lane. North of Bestgate Road, the highway leaves the commercial area, curves to the northwest, reduces to two lanes. MD 178 passes the historic home Iglehart in the eponymous hamlet, where the highway passes Old Generals Highway. A portion of the loop of old alignment is MD 798. MD 178 continues northwest and passes the historic home Belvoir before heading northeast of the Anne Arundel County Fairgrounds and entering the center of Crownsville. In the village, the highway passes St. Paul's Chapel at the corner of Crownsville Road, which leads south to the grounds of the seasonal Maryland Renaissance Festival. At the north end of Crownsville, MD 178 intersects Herald Harbor Road, which leads to the namesake beach community on the Severn River; the state highway meets the eastern end of interchange ramps from I-97. MD 178 continues northwest past the Rising Sun Inn and Sunrise Beach Road, which leads to another riverside community, Arden-on-the-Severn.
At the Cross Roads Church, the highway intersects Millersville Road, which provides access to the historic home Bunker Hill and the village of Millersville on the west side of I-97. MD 178 curves north and reaches its northern terminus at Veterans Highway, a county highway that parallels I-97 between Millersville and Glen Burnie. Generals Highway follows the path of an Annapolis–Philadelphia post road established by 1733; the highway is so named because it was traveled by George Washington on his journey from New York to Annapolis acting as the capital of the United States, to resign his commission as Commander-in-Chief of the Continental Army in December 1783. George Washington was greeted and escorted the remaining distance to Annapolis by a group of prominent citizens from the Three Mile Oak, a prominent tree located 3 miles from the Maryland State House; the Three Mile Oak was located at what is today the southern terminus of MD 178. When the Maryland State Roads Commission designated a system of roads to improve in 1909, much of the Generals Highway was included as part of a second highway between Baltimore and Annapolis, after the Baltimore–Annapolis Boulevard that became MD 2.
The proposed highway headed south along Generals Highway from Glen Burnie to Crownsville, along what are now MD 3 Business, I-97, MD 178 south on Crownsville Road to the proposed highway that became US 50. The proposed highway south and east of Dorrs Corner, the site of MD 178's northern terminus, was not shifted from Crownsville Road to Generals Highway until 1930, by which time only short portions of the highway had been paved; the first portion of MD 178 to be constructed was a small segment of concrete road south from the southern end of Old Generals Highway at Iglehart by 1923. This section was connected to US 50 by another section of concrete road in 1928; the portion of MD 178 from Dorrs Corner to Crownsville was placed under construction in 1930. The state highway was complete as a concrete road from MD 3 to Sherwood Forest Road just north of Iglehart in 1933. MD 178 was marked despite a gap in the state highway remaining at Iglehart. Within a year of the highway's completion, the Maryland State Roads Commission recommended the highway be widened from 15 to 16 feet to 20 feet along its entire length.
The state highway was widened from Dorrs Corner to Sherwood Forest Road in 1940. The gap in the state highway at Iglehart remained until the old road was bypassed in 1956, leaving behind MD 798. MD 178's interchange ramps with I-97 opened as the easternmost portion of MD 32 in 1972, bypassing the portion of the highway from Dorrs Corner to Crownsville; the rest of the route from Crownsville to Parole remained part of the primary highway on the western Baltimore–Annapolis highway until I-97 opened from US 50 and US 301 to Dorrs Corner in April 1989. The entire route is in Anne Arundel County. MD 178A is the designation for a 0.28-mile old section of Generals Highway next to the state highway's northern terminus near Millersville. The highway forms a curve east of the junction of MD 178 and Veterans Highway that intersects both highways on a tangent. MD 178A is two lanes and lined with houses except for a pair of one-way northbound segments on both ends. MD 178A follows what was the northernmost portion of MD 178 to meet what is now Veterans Highway at an acute intersection at Dorrs Corner.
Juliette Morillot is a French journalist. She is the author of several books about North Korea. Morillot was born in 1959 in France, her parents were English teachers. Morillot graduated from the École du Louvre, she learned to speak Czech, Korean and Russian at the Institut national des langues et civilisations orientales. Morillot taught at the University of Seoul in 1988, she has taught at the École de guerre. Morillot was a contributing writer to Jeune Afrique from 2005 to 2015, she became the editor of La Revue in 2012, followed by Asyalist. Morillot is the author of several books, she was awarded the Prix du meilleur livre de géopolitique 2018 from the Grenoble Geopolitics Festival for La Corée du Nord en 100 questions in 2018. Morillot, Juliette. Tout sur... la Corée, le pays du matin clair. Paris: Souffles. ISBN 9782876580220. OCLC 63132553. Morillot, Juliette. La Corée, chamanes et gratte-ciel. Paris: Autrement. ISBN 9782862607825. OCLC 39294742. Morillot, Juliette. La Corée: Terre des Esprits. Paris: Hermé.
ISBN 9782866653750. OCLC 53229823. Malovic, Dorian. Evadés de Corée du Nord: Témoignages. Paris: Belfond. ISBN 9782714440570. OCLC 718010942. Morillot, Juliette. Les Larmes Bleues. Paris: Pocket. ISBN 9782266197281. OCLC 763061529. Morillot, Juliette. Les Sacrifiés. Paris: Belfond. ISBN 9782298056358. OCLC 1040430788. Malovic, Dorian. La Corée du Nord en 100 questions. Paris: Tallandier. ISBN 9791021031449. OCLC 1021886451. Malovic, Dorian. Le Monde selon Kim Jong-un. Paris: Robert Laffont. ISBN 9782221216675. OCLC 1023610327