A chemical element is a species of atom having the same number of protons in their atomic nuclei. For example, the atomic number of oxygen is 8, so the element oxygen describes all atoms which have 8 protons. In total, 118 elements have been identified; the first 94 occur on Earth, the remaining 24 are synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have radionuclides, which decay over time into other elements. Iron is the most abundant element making up Earth, while oxygen is the most common element in the Earth's crust. Chemical elements constitute all of the ordinary matter of the universe; however astronomical observations suggest that ordinary observable matter makes up only about 15% of the matter in the universe. The remainder is dark matter; the two lightest elements and helium, were formed in the Big Bang and are the most common elements in the universe. The next three elements were formed by cosmic ray spallation, are thus rarer than heavier elements.

Formation of elements with 6 to 26 protons occurs in main sequence stars via stellar nucleosynthesis. The high abundance of oxygen and iron on Earth reflects their common production in such stars. Elements with greater than 26 protons are formed by nucleosynthesis in supernovae, when they explode, blast these elements as supernova remnants far into space, where they may become incorporated into planets when they are formed; the term "element" is used for atoms with a given number of protons as well as for a pure chemical substance consisting of a single element. For the second meaning, the terms "elementary substance" and "simple substance" have been suggested, but they have not gained much acceptance in English chemical literature, whereas in some other languages their equivalent is used. A single element can form multiple substances differing in their structure; when different elements are chemically combined, with the atoms held together by chemical bonds, they form chemical compounds. Only a minority of elements are found uncombined as pure minerals.

Among the more common of such native elements are copper, gold and sulfur. All but a few of the most inert elements, such as noble gases and noble metals, are found on Earth in chemically combined form, as chemical compounds. While about 32 of the chemical elements occur on Earth in native uncombined forms, most of these occur as mixtures. For example, atmospheric air is a mixture of nitrogen and argon, native solid elements occur in alloys, such as that of iron and nickel; the history of the discovery and use of the elements began with primitive human societies that found native elements like carbon, sulfur and gold. Civilizations extracted elemental copper, tin and iron from their ores by smelting, using charcoal. Alchemists and chemists subsequently identified many more; the properties of the chemical elements are summarized in the periodic table, which organizes the elements by increasing atomic number into rows in which the columns share recurring physical and chemical properties. Save for unstable radioactive elements with short half-lives, all of the elements are available industrially, most of them in low degrees of impurities.

The lightest chemical elements are hydrogen and helium, both created by Big Bang nucleosynthesis during the first 20 minutes of the universe in a ratio of around 3:1 by mass, along with tiny traces of the next two elements and beryllium. All other elements found in nature were made by various natural methods of nucleosynthesis. On Earth, small amounts of new atoms are produced in nucleogenic reactions, or in cosmogenic processes, such as cosmic ray spallation. New atoms are naturally produced on Earth as radiogenic daughter isotopes of ongoing radioactive decay processes such as alpha decay, beta decay, spontaneous fission, cluster decay, other rarer modes of decay. Of the 94 occurring elements, those with atomic numbers 1 through 82 each have at least one stable isotope. Isotopes considered stable are those. Elements with atomic numbers 83 through 94 are unstable to the point that radioactive decay of all isotopes can be detected; some of these elements, notably bismuth and uranium, have one or more isotopes with half-lives long enough to survive as remnants of the explosive stellar nucleosynthesis that produced the heavy metals before the formation of our Solar System.

At over 1.9×1019 years, over a billion times longer than the current estimated age of the universe, bismuth-209 has the longest known alpha decay half-life of any occurring element, is always considered on par with the 80 stable elements. The heaviest elements undergo radioactive decay with half-lives so short that they are not found in nature and must be synthesized; as of 2010, there are 118 known elements (in this context, "known" means observed well enoug

The Snake River Land Company Residence and Office are structures associated with John D. Rockefeller, Jr.'s acquisition of land in Jackson Hole, United States. Under the guise of the Snake River Land Company, Rockefeller bought much of the land that he donated to the National Park Service, first as Jackson Hole National Monument and a year as Grand Teton National Park; the buildings are located in the community of Moran. They served as the residence and office for SRLC vice president Harold Fabian and foreman J. Allan from 1930 to 1945; the buildings are still used by the National Park Service. The property was owned from 1926 to 1930 by John Hogan, a retired politician from the eastern United States; the Snake River Land Company bought the property in 1930. The ranch buildings were built by John Hogan, a retired politician from the East, who bought William Carter's homestead in 1926 for use as a guest ranch and fox farm. Hogan built the blacksmith shop. Four guest cabins an ice house no longer exist.

The Snake River Land Company bought the property from Hogan in 1930, adding onto the house and building a log garage. The house known as Building 117 and as "Buffalo Dorm", is a 1-1/2 story log structure dating to circa 1926; the original central gabled block was flanked by shed-roofed extensions on the east and west sides, with the stone chimney centered in the eastern side. A shed-roofed addition covers the front of the central unit. A further gable-roofed addition covers much of the western shed wing; the main entry opens into a large office, with a living room to the north and a kitchen and pantry to the west. The sun room, an enclosed former porch, is reached from the living room; the living room has a raised ceiling. The stone fireplace dominates the room, with bookshelves to either side. Three bedrooms and a bathroom are in the northwestern portion of the house. On the second floor a central landing leads to two bedrooms on the south and southeast and a storage loft to the northeast; the interiors contribute to the ranch's significance.

Harold and Josephine Fabian moved to the Geraldine Lucas Homestead in 1945. The Jackson Hole Preserve, which had succeeded the Snake River Land Company, used the house as a residence for Sonny Allen, manager of the nearby Jackson Hole Wildlife Park at Oxbow Bend; the house was used as a dormitory before being abandoned. April 2019 work started restoring the home for Park rangers The house was placed on the National Register of Historic Places in 2006. Geraldine Lucas Homestead-Fabian Place Historic District Historical buildings and structures of Grand Teton National Park Snake River Land Company Office at Grand Teton National Park Snake River Land Company Historic Structure Report

The monarchy of Solomon Islands is a system of government in which a constitutional monarch is the head of state of Solomon Islands. The present monarch is Queen Elizabeth II, the head of state of fifteen other Commonwealth realms; the Queen's constitutional roles in Solomon Islands are delegated to the Governor-General of Solomon Islands. The Commonwealth of Nations has over 50 member states, of which, sixteen are Commonwealth realms that recognise, Elizabeth II as their monarch and therefore head of state; each realm, including Solomon Islands, is a independent state. Elizabeth II exercises her sovereignty only as Queen of Solomon Islands and on all matters relating to Solomon Islands, the monarch is advised by Solomon Islands ministers; the monarch of Solomon Islands is represented by the Governor-General of Solomon Islands, a citizen of Solomon Islands elected for a five-year term by the national parliament. Formally, the monarch appoints the Governor-General on the advice of parliament; the current Governor-General is the Anglican Archbishop Emeritus of Melanesia and former Bishop of the Diocese of Central Melanesia, David Vunagi, first elected in 2019.

Governors-General must meet the same eligibility requirements as members of parliament and can serve no more than two terms. This arrangement came into being subsequent to the Balfour Declaration of 1926, which provided the dominions the right to be considered equal to Britain, rather than subordinate; the monarchy thus ceased to be an British institution, although it has been called "British" since for reasons historical, of convenience. The Royal and Parliamentary Titles Act, 1927 was the first indication of this shift in law, further elaborated in the Statute of Westminster, 1931. Solomon Islands gained self-government in 1976 following the independence of neighbouring Papua New Guinea from Australia in 1975. Independence was granted in 1978, establishing Solomon Islands as a sovereign democratic state, with the Queen as head of state; the new constitution, providing for responsible status within the Commonwealth, took effect under The Solomon Islands Independence Order 1978, an order in council, requested by the Legislative Assembly.

It was made under the Foreign Jurisdiction Act 1890, came into operation on 7 July 1978. Under the constitution the oath of allegiance is a declaration of allegiance to "Her Majesty Queen Elizabeth II, Her Heirs and Successors"; the monarch's duties are performed by the Governor-General. The Governor-General represents the monarch on ceremonial occasions such as the opening of parliament, the presentation of honours and military parades. Under the constitution, he or she is given authority to act in some matters, for example in appointing and disciplining officers of the civil service, in proroguing parliament; as in the other Commonwealth realms, the monarch's role is entirely symbolic and cultural. The powers that are constitutionally hers are exercised wholly upon the advice of the cabinet, made up of Ministers of the Crown; the royal family visits the islands. The Queen has visited twice: in February 1974 and in October 1982. Prince Philip, Duke of Edinburgh, accompanied the Queen on both occasions, visited without the Queen, in 1959 and 1971.

Princess Anne and Mark Phillips visited in 1974 and the Duke and the Duchess of Cambridge visited in 2012. Succession to the throne in Solomon Islands is identical to the succession to the British throne; the heir apparent is Charles. No Commonwealth realm can alter the succession without the agreement of the other realms. Under the Statute of Westminster, Solomon Islands has a common monarchy with Britain and the other Commonwealth realms, Solomon Islands cannot change the rules of succession without the unanimous consent of the other realms, unless explicitly leaving the shared monarchy relationship by means of a constitutional amendment; this situation applies symmetrically in all the other realms, including the UK. In Solomon Islands, the Queen's official title is: Queen of Solomon Islands and of Her other Realms and Territories, Head of the Commonwealth