1.
Machars
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The Machars is a peninsula in Galloway in the south-west of Scotland. The word is derived from the Gaelic word Machair meaning low-lying or level land, although there are no high peaks in the Machars, it is not flat and would best be described as undulating or rolling. The North Atlantic Drift or Gulf Stream creates a mild climate, the Machars peninsula is roughly defined by a northern boundary stretching from Newton Stewart to Glenluce, the only other boundary being the sea. The 40-mile coastline has enormous variety, starting with the mud-flats of Wigtown on the east facing Wigtown Bay, down to the sandy beach at Rigg Bay in Garlieston. The coastline then rises to form dramatic cliffs as it passes the ruins of Cruggleton Castle, dropping a little at Portyerrock Bay and the Isle of Whithorn, past the southern tip of the peninsula, the shoreline leaves Wigtown Bay and becomes part of Luce Bay. The cliffs continue as far as the sandy beach at Monreith. A combination of rocky shoreline, sandy beaches and cliffs continues as far as Auchenmalg, another tributary of the Bladnoch is the large stream the Water of Malzie which rises in the large expanses of peat bog near the Old Place of Mochrum before meeting the Bladnoch near Corzmalie. In fact up until recent decades a large scale creamery was to be found at Sorbie although this has now closed, the other principal settlements on the peninsula are, Kirkcowan, Whithorn, Kirkinner, Sorbie, Mochrum, Elrig, Bladnoch and Whauphill. There are a number of lochs in the area including Mochrum Loch, Castle Loch. The area is rich in remains, mainly in the form of standing stones and cup. The most notable of these are Torhousekie and Drumtroddan, in Castle Loch near The Old Place of Mochrum are the remains of several crannogs. The primary industry in the area was agriculture, though today the tourist industry employs more people. Burrow Head is about eighteen miles from Point of Ayre on the Isle of Man, the Machars is also home to the former RAF Wigtown. Although the site consisted of grass runways, flooding of the land soon caused these to become unusable. Despite considerable deterioration the airfield remains intact, with the control tower still standing and nearly all the perimeter. Furthermore, the bases of many of the hangars and other buildings can still be seen on the ground. Today much of the land has reverted to use, with the site becoming popular for locals to conduct leisure activities – such as walking or cycling. Saint Ninian first brought Christianity to what-would-become Scotland via the Machars, founding a small church at the Isle of Whithorn from which a mediæval cathedral later sprang at Whithorn
2.
Berneray (North Uist)
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Berneray is an island and community in the Sound of Harris, Scotland. It is one of fifteen inhabited islands in the Outer Hebrides and it is famed for its rich and colourful history which has attracted much tourism. With an area of 10.1 square kilometres, Berneray rises to a height of 305 feet at Beinn Shlèibhe and 278 feet at Borve Hill, there is strong evidence that points to Berneray being inhabited since the Bronze Age, and possibly before. The island is scattered with ancient sacred sites, stone circles, signs of Viking inhabitation and historical buildings, the name Berneray is from the Old Norse Bjarnar-øy and means either Bjorns island or possibly bear island. More recently Gaelic speakers have also used Beàrnaraigh Uibhist, i. e. Berneray of Uist to refer to the northern Berneray, in common with most islands in the Outer Hebrides, the population declined during the 19th and 20th centuries. However, the past few years has seen a stabilisation, the islands population was 138 as recorded by the 2011 census a small rise since 2001 when there were 136 usual residents. During the same period Scottish island populations as a whole grew by 4% to 103,702, most people on Berneray speak Scottish Gaelic, many as a first language. Berneray is known as the birthplace of the giant Angus MacAskill, the west beach, a three-mile stretch of wide, clean and often deserted sand, is widely acclaimed. The main industries are fishing, crofting, media/IT and tourism, broadband internet provision became available in January 2006, giving an incentive to people wishing to relocate to Berneray and helping sustain the population and community. A key feature of Berneray is its machair, the machair is a coastal plain made up of windblown shell sand. The machair is ploughed in rotation, giving a patchwork of crops, Berneray has a particularly fine machair, a result of careful husbandry by the island’s crofters, helped by the absence of rabbits. The youth hostel on Berneray is part of the Gatliff Hebridean Hostels Trust, the hostel consists of two restored black houses and is located at a magnificent setting overlooking the sound of Harris. Possibly the greatest change in modern times occurred in 1999 when the causeway opened between Berneray and Otternish on North Uist and this has eased travelling on and off the island, improving employment prospects and accelerating the carriage of produce. The causeway contains culverts that allow the passage of otters. The causeway was opened by Prince Charles in April 1999. Berneray is served by local bus services from Lochmaddy on North Uist. Most services are operated by Grenitote Travel, with funding from Comhairle nan Eilean Siar, Berneray is also linked to Harris, Scotland via Leverburgh by the ferry MV Loch Portain, operated by Caledonian MacBrayne. The CalMac ferry MV Loch Bhrusda is named after the largest loch on Berneray and it can occasionally be seen relieving for MV Loch Portain
3.
Outer Hebrides
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The Outer Hebrides, also known as the Western Isles, Innse Gall or the Long Isle or Long Island, is an island chain off the west coast of mainland Scotland. The islands are geographically coextensive with Comhairle nan Eilean Siar, one of the 32 unitary council areas of Scotland. They form part of the Hebrides, separated from the Scottish mainland and from the Inner Hebrides by the waters of the Minch, the Little Minch, Scottish Gaelic is the predominant spoken language, although in a few areas English speakers form a majority. Most of the islands have a formed from ancient metamorphic rocks. The 15 inhabited islands have a population of 27,100. From Barra Head to the Butt of Lewis is roughly 210 kilometres, There are various important prehistoric structures, many of which pre-date the first written references to the islands by Roman and Greek authors. The Western Isles became part of the Norse kingdom of the Suðreyjar, control of the islands was then held by clan chiefs, principal of whom were the MacLeods, MacDonalds, Mackenzies and MacNeils. The Highland Clearances of the 19th century had an effect on many communities. Much of the land is now under control and commercial activity is based on tourism, crofting, fishing. Sea transport is crucial and a variety of services operate between the islands and to mainland Scotland. Modern navigation systems now minimise the dangers but in the past the stormy seas have claimed many ships, religion, music and sport are important aspects of local culture, and there are numerous designated conservation areas to protect the natural environment. The islands form an archipelago whose major islands are Lewis and Harris, North Uist, Benbecula, South Uist, and Barra. Lewis and Harris has an area of 217,898 hectares and is the largest island in Scotland and it incorporates Lewis in the north and Harris in the south, both of which are frequently referred to as individual islands, although they are connected by land. The island does not have a name in either English or Gaelic. The largest islands are deeply indented by arms of the sea such as Loch Ròg, Loch Seaforth, There are also more than 7,500 freshwater lochs in the Outer Hebrides, about 24% of the total for the whole of Scotland. North and South Uist and Lewis in particular have landscapes with a percentage of fresh water. Harris has fewer large bodies of water but has innumerable small lochans, Loch Langavat on Lewis is 11 kilometres long, and has several large islands in its midst, including Eilean Mòr. Although Loch Suaineabhal has only 25% of Loch Langavats surface area, of Loch Sgadabhagh on North Uist it has been said that there is probably no other loch in Britain which approaches Loch Scadavay in irregularity and complexity of outline
4.
Plain
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In geography, a plain is a flat, sweeping landmass that generally does not change much in elevation. Plains occur as lowlands along the bottoms of valleys or on the doorsteps of mountains, as coastal plains, and as plateaus or uplands. In a valley, a plain is enclosed on two sides but in other cases a plain may be delineated by a complete or partial ring of hills, where a geological region contains more than one plain, they may be connected by a pass. Coastal plains would mostly rise from sea level until they run into elevated features such as mountains or plateaus, plains are one of the major landforms on earth, where they are present on all continents, and would cover more than one-third of the world’s land area. Plains may have formed from flowing lava, deposited by water, ice, wind, or formed by erosion by these agents from hills. Plains would generally be under the grassland, steppe, savannah or tundra biomes, in a few instances, deserts and rainforests can also be plains. Structural plains are relatively undisturbed horizontal surfaces of the Earth and they are structurally depressed areas of the world that make up some of the most extensive natural lowlands on the Earths surface. Erosional plains have been leveled by various agents of such as running water, rivers, wind and glacier which wear out the rugged surface. Plain resulting from the action of these agents of denudation are called peneplains while plains formed from wind action are called pediplains, depositional plains formed by the deposition of materials brought by various agents of transportation such as rivers, wind, waves, and glaciers. Their fertility and economic relevance depend greatly on the types of sediments that are laid down, flood plain, adjacent to a stream, river, lake or wetland that experiences occasional or periodic flooding. Scroll plain, a plain through which a river meanders with a low gradient. Lacustrine plain, a plain that originally formed in a lacustrine environment, lava plain, formed by sheets of flowing lava. Glacial plains, formed by the movement of glaciers under the force of gravity, Sandur, sandar consist mainly of stratified gravel and sand. Till plain, a plain of glacial till that forms when a sheet of ice becomes detached from the body of a glacier. Till plains are composed of unsorted material of all sizes, abyssal plain, a flat or very gently sloping area of the deep ocean basin. Planitia, the Latin word for plain, is used in the naming of plains on extraterrestrial objects, such as Hellas Planitia on Mars or Sedna Planitia on Venus
5.
Coast
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A coastline or a seashore is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox, the term coastal zone is a region where interaction of the sea and land processes occurs. Both the terms coast and coastal are often used to describe a location or region, for example, New Zealands West Coast. Edinburgh for example is a city on the coast of Scotland, a pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the hand, can refer to parts of the land which adjoin any large body of water, including oceans. Similarly, the related term refers to the land alongside or sloping down to a river or to a body of water smaller than a lake. Bank is also used in parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. According to the UN atlas, 44% of people live within 150 kilometres of the sea, tides often determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, the tidal range is influenced by the size and shape of the coastline. Tides do not typically cause erosion by themselves, however, tidal bores can erode as the waves surge up river estuaries from the ocean. Waves erode coastline as they break on shore releasing their energy, the larger the wave the more energy it releases and the more sediment it moves. Coastlines with longer shores have more room for the waves to disperse their energy, while coasts with cliffs and short shore faces give little room for the wave energy to be dispersed. In these areas the wave energy breaking against the cliffs is higher, sediment deposited by waves comes from eroded cliff faces and is moved along the coastline by the waves. This forms an abrasion or cliffed coast, sediment deposited by rivers is the dominant influence on the amount of sediment located on a coastline. Today riverine deposition at the coast is often blocked by dams and other human regulatory devices, like the ocean which shapes them, coasts are a dynamic environment with constant change. The coast and its adjacent areas on and off shore are an important part of a local ecosystem, Salt marshes and beaches also support a diversity of plants, animals and insects crucial to the food chain. The high level of biodiversity creates a level of biological activity. More and more of the people live in coastal regions
6.
Ireland
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Ireland is an island in the North Atlantic. It is separated from Great Britain to its east by the North Channel, the Irish Sea, Ireland is the second-largest island of the British Isles, the third-largest in Europe, and the twentieth-largest on Earth. Politically, Ireland is divided between the Republic of Ireland, which covers five-sixths of the island, and Northern Ireland, in 2011, the population of Ireland was about 6.4 million, ranking it the second-most populous island in Europe after Great Britain. Just under 4.6 million live in the Republic of Ireland, the islands geography comprises relatively low-lying mountains surrounding a central plain, with several navigable rivers extending inland. The island has lush vegetation, a product of its mild, thick woodlands covered the island until the Middle Ages. As of 2013, the amount of land that is wooded in Ireland is about 11% of the total, there are twenty-six extant mammal species native to Ireland. The Irish climate is moderate and classified as oceanic. As a result, winters are milder than expected for such a northerly area, however, summers are cooler than those in Continental Europe. Rainfall and cloud cover are abundant, the earliest evidence of human presence in Ireland is dated at 10,500 BC. Gaelic Ireland had emerged by the 1st century CE, the island was Christianised from the 5th century onward. Following the Norman invasion in the 12th century, England claimed sovereignty over Ireland, however, English rule did not extend over the whole island until the 16th–17th century Tudor conquest, which led to colonisation by settlers from Britain. In the 1690s, a system of Protestant English rule was designed to materially disadvantage the Catholic majority and Protestant dissenters, with the Acts of Union in 1801, Ireland became a part of the United Kingdom. Northern Ireland saw much civil unrest from the late 1960s until the 1990s and this subsided following a political agreement in 1998. In 1973 the Republic of Ireland joined the European Economic Community while the United Kingdom, Irish culture has had a significant influence on other cultures, especially in the fields of literature. Alongside mainstream Western culture, an indigenous culture exists, as expressed through Gaelic games, Irish music. The culture of the island shares many features with that of Great Britain, including the English language, and sports such as association football, rugby, horse racing. The name Ireland derives from Old Irish Eriu and this in turn derives from Proto-Celtic *Iveriu, which is also the source of Latin Hibernia. Iveriu derives from a root meaning fat, prosperous, during the last glacial period, and up until about 9000 years ago, most of Ireland was covered with ice, most of the time
7.
Scotland
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Scotland is a country that is part of the United Kingdom and covers the northern third of the island of Great Britain. It shares a border with England to the south, and is surrounded by the Atlantic Ocean, with the North Sea to the east. In addition to the mainland, the country is made up of more than 790 islands, including the Northern Isles, the Kingdom of Scotland emerged as an independent sovereign state in the Early Middle Ages and continued to exist until 1707. By inheritance in 1603, James VI, King of Scots, became King of England and King of Ireland, Scotland subsequently entered into a political union with the Kingdom of England on 1 May 1707 to create the new Kingdom of Great Britain. The union also created a new Parliament of Great Britain, which succeeded both the Parliament of Scotland and the Parliament of England. Within Scotland, the monarchy of the United Kingdom has continued to use a variety of styles, titles, the legal system within Scotland has also remained separate from those of England and Wales and Northern Ireland, Scotland constitutes a distinct jurisdiction in both public and private law. Glasgow, Scotlands largest city, was one of the worlds leading industrial cities. Other major urban areas are Aberdeen and Dundee, Scottish waters consist of a large sector of the North Atlantic and the North Sea, containing the largest oil reserves in the European Union. This has given Aberdeen, the third-largest city in Scotland, the title of Europes oil capital, following a referendum in 1997, a Scottish Parliament was re-established, in the form of a devolved unicameral legislature comprising 129 members, having authority over many areas of domestic policy. Scotland is represented in the UK Parliament by 59 MPs and in the European Parliament by 6 MEPs, Scotland is also a member nation of the British–Irish Council, and the British–Irish Parliamentary Assembly. Scotland comes from Scoti, the Latin name for the Gaels, the Late Latin word Scotia was initially used to refer to Ireland. By the 11th century at the latest, Scotia was being used to refer to Scotland north of the River Forth, alongside Albania or Albany, the use of the words Scots and Scotland to encompass all of what is now Scotland became common in the Late Middle Ages. Repeated glaciations, which covered the land mass of modern Scotland. It is believed the first post-glacial groups of hunter-gatherers arrived in Scotland around 12,800 years ago, the groups of settlers began building the first known permanent houses on Scottish soil around 9,500 years ago, and the first villages around 6,000 years ago. The well-preserved village of Skara Brae on the mainland of Orkney dates from this period and it contains the remains of an early Bronze Age ruler laid out on white quartz pebbles and birch bark. It was also discovered for the first time that early Bronze Age people placed flowers in their graves, in the winter of 1850, a severe storm hit Scotland, causing widespread damage and over 200 deaths. In the Bay of Skaill, the storm stripped the earth from a large irregular knoll, when the storm cleared, local villagers found the outline of a village, consisting of a number of small houses without roofs. William Watt of Skaill, the laird, began an amateur excavation of the site, but after uncovering four houses
8.
North Uist
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North Uist is an island and community in the Outer Hebrides of Scotland. According to the 2011 Census, there are 887 Gaelic speakers on North Uist, North Uist is the tenth largest Scottish island and the thirteenth largest island surrounding Great Britain. It has an area of 117 square miles, slightly smaller than South Uist, North Uist is connected by causeways to Benbecula via Grimsay, to Berneray, and to Baleshare. With the exception of the south east, the island is very flat, some of the lochs contain a mixture of fresh and tidal salt water, giving rise to some complex and unusual habitats. The northern part of the island is part of the South Lewis, Harris and North Uist National Scenic Area, the main settlement on the island is Lochmaddy, a fishing port and home to a museum, an arts centre and a camera obscura. Caledonian MacBrayne ferries sail from the village to Uig on Skye, as well as from the island of Berneray, Lochmaddy also has Taigh Chearsabhagh - a museum and arts centre with a cafe, small shop and post office service. Nearby is the Uist Outdoor Centre, the islands main villages are Sollas, Hosta, Tigharry, Hougharry, Paible, Grimsay and Cladach Kirkibost. Other settlements include Clachan Carinish, Knockquien, Port nan Long, Greinetobht and Scolpaig, Loch Portain is a small hamlet on the east coast – some 9 miles from Lochmaddy, with sub areas of Cheesebay and Hoebeg. According to the 2001 census North Uist had a population of 1,271, the Vikings arrived in the Hebrides in 800AD where they had large settlements. The island is known for its birdlife, including corncrakes, Arctic terns, gannets, corn buntings, the RSPB has a nature reserve at Balranald. Despite limited facilities, the athletics club has performed well at local, regional and national athletics competitions. In Donald Munros A Description of the Western Isles of Scotland Called Hybrides of 1549, North Uist, Benbecula and South Uist are described as one island of Ywst. Starting in the south of island, he described the division between South Uist and Benbecula where the end heirof the sea enters, and cuts the countrey be ebbing and flowing through it. Further north of Benbecula he described North Uist as this countrey is called Kenehnache of Ywst, that is in Englishe, some have given the etymology of Uist from Old Norse meaning west, much like Westray in the Orkney Islands. Another speculated derivation from Uist in Old Norse is Ívist, derived from vist meaning an abode, dwelling, a Gaelic etymology is also possible, with I-fheirste meaning Crossings-island or Fords-island, derived from I meaning island and fearsad meaning estuary, sand-bank, passage across at ebb-tide. Place-names derived from fearsad include Fersit, and Belfast, Mac an Tàilleir suggests that a Gaelic derivation of Uist may be corn island. In the 18th century the population of the combined Uists rose dramatically. In 1755, the Uists estimated combined population was 4,118, by 1794 it rose to 6,668, the pre-clearance population of North Uist was about 5,000 and it has dwindled to about 1,300 in 2011
9.
Harris, Scotland
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Harris is the southern and more mountainous part of Lewis and Harris, the largest island in the Outer Hebrides, Scotland. Although not a itself, Harris is often referred to as the Isle of Harris, which is the former postal county. A person from Harris is known as a Hearach, according to the 2011 Census, there are 1,212 Gaelic speakers in the Harris area. Harris is most likely to be the island referred to as Adru on Ptolemys map of the British Isles, in Old Norse, a Hérað was a type of administrative district, and the name may derive from that. An alternative origin is the Norse Hærri, meaning higher - a reference to the high hills, most of the place names on Harris are Gaelicized Old Norse. The Gaelic name Na Hearadh was also a term for the Rinns of Islay. Harris divides naturally into northern and southern parts which are separated by West and East Loch Tarbert and these halves are joined by a narrow isthmus at the main settlement of Tarbert. The bedrock of Harris is largely Lewisian gneisses, which were laid down in the Precambrian period, one of these intrusions forms the summit plateau of the mountain Roinebhal. The rock here is anorthosite, and is similar in composition to rocks found in the mountains of the Moon, Harris is a part of historic Inverness-shire, and was administered as such under older administrative divisions. In the 2001 census, Harris had a resident population of 1,916. It is part of the South Lewis, Harris and North Uist National Scenic Area, North Harris, adjoining Lewis, contains Clisham, the highest mountain in the Outer Hebrides at 799 metres. Beyond Tarbert, the furthest settlement is Hushinish on the west coast, a bridge from the east coast links Harris to the island of Scalpay. In March 2003 the 25, 300-hectare North Harris Estate was purchased by the North Harris Trust, in April 2006 the Trust hosted the Highlands and Islands Community Energy Company conference Community Energy, Leading from the Edge in Tarbert. In early 2008 the Trust received planning consent for three 86 metre wind turbines to be located at Monan. In 2008 Mike Russell, the Scottish environment minister announced that the North Harris Trust had begun canvassing local opinion about a proposal to create Scotlands third national park in the area. The southern part of Harris is less mountainous, with numerous unspoilt and its main settlements are Rodel, known for its medieval kirk of St. Clement, the most elaborate surviving medieval church in the Hebrides after Iona Abbey, and Leverburgh. A ferry sails from the latter to Berneray, an island off the coast of North Uist, the road which runs along the east coast of south Harris is known colloquially as the Golden Road as it cost so much money to build, when it was built in 1897. It runs from Tarbert to Rodel through the area of Harris known as Bays and through the townships of Lickisto, Geocrab, Manish
10.
Lewis
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Lewis is the northern part of Lewis and Harris, the largest island of the Western Isles or Outer Hebrides. The total area of Lewis is 683 square miles, Lewis is, in general, the lower-lying part of the island, the other part, Harris, is more mountainous. Due to its flatter, more land, Lewis contains three-quarters of the population of the Western Isles. The islands diverse habitats are home to an assortment of flora and fauna, such as the eagle, red deer and seal. Lewis has a Presbyterian tradition and a rich history and it was once part of the Norse Kingdom of Mann and the Isles. Today, life is different from elsewhere in Scotland, with Sabbath observance. Lewis has a cultural heritage as can be seen from its myths and legends as well as the local literary. The Gaelic name Leòdhas may be derived from Norse Ljoðahús, although other origins have been suggested – most notably the Gaelic leogach and it is probably the place referred to as Limnu by Ptolemy, which also means marshy. It is also known as the Isle of Lewis, another name usually used in a cultural or poetic context is Eilean an Fhraoich. Although this refers to the whole of the island of Lewis and Harris, the earliest archaeological remains date from about 5,000 years ago. At that time, people began to settle in permanent farms rather than following their herds, the small houses of these people have been found throughout the Western Isles, in particular, at Dail Mhor, Carloway. The more striking great monuments of this period are the temples, about 500 BC, island society moved into the Iron Age. The buildings became larger and more prominent, culminating in the brochs – circular, the best remaining example of a broch in Lewis is at Dùn Chàrlabhaigh. The Scots arrived during the first centuries AD, bringing the Gaelic language with them, as Christianity began to spread through the islands in the 6th and later centuries, following Columban missionaries, Lewis was inhabited by the Picts. In the 9th century AD, the Vikings began to settle on Lewis, the Norse invaders intermarried with local people and abandoned their pagan beliefs. At that time, rectangular buildings began to round ones. Lewis became part of the Kingdom of Mann and the Isles, the Lewis chessmen, found on the island in 1831, date from the time of Viking rule. The people were called the Norse Gaels or Gall-Ghàidheil, reflecting their mixed Scandinavian/Gaelic background, the Norse language persists in many island placenames and some personal names to this day, although the latter are fairly evenly spread across the Gàidhealtachd
11.
Calcium carbonate
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Calcium carbonate is a chemical compound with the formula CaCO3. It is a substance found in rocks as the minerals calcite and aragonite and is the main component of pearls and the shells of marine organisms, snails. Calcium carbonate is the ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It is medicinally used as a supplement or as an antacid. Calcium carbonate shares the properties of other carbonates. CaCO3 + CO2 + H2O → Ca2 This reaction is important in the erosion of rock, forming caverns. An unusual form of calcium carbonate is the hexahydrate, ikaite, ikaite is stable only below 6 °C. The vast majority of calcium used in industry is extracted by mining or quarrying. Pure calcium carbonate, can be produced from a quarried source. Alternatively, calcium carbonate is prepared from calcium oxide, other forms can be prepared, the denser, orthorhombic λ-CaCO3 and μ-CaCO3, occurring as the mineral vaterite. The aragonite form can be prepared by precipitation at temperatures above 85 °C, calcite contains calcium atoms coordinated by 6 oxygen atoms, in aragonite they are coordinated by 9 oxygen atoms. The vaterite structure is not fully understood, magnesium carbonate MgCO3 has the calcite structure, whereas strontium and barium carbonate adopt the aragonite structure, reflecting their larger ionic radii. Calcite, aragonite and vaterite are pure calcium carbonate minerals, industrially important source rocks which are predominantly calcium carbonate include limestone, chalk, marble and travertine. Eggshells, snail shells and most seashells are predominantly calcium carbonate, oyster shells have enjoyed recent recognition as a source of dietary calcium, but are also a practical industrial source. While not practical as a source, dark green vegetables such as broccoli. Beyond Earth, strong evidence suggests the presence of Calcium carbonate on Mars, signs of Calcium Carbonate have been detected at more than one location. This provides some evidence for the past presence of liquid water, Carbonate is found frequently in geologic settings and constitute an enormous carbon reservoir. Calcium carbonate occurs as aragonite, calcite and dolomite, the carbonate minerals form the rock types, limestone, chalk, marble, travertine, tufa, and others
12.
PH
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In chemistry, pH is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the concentration, measured in units of moles per liter. More precisely it is the negative of the logarithm to base 10 of the activity of the hydrogen ion, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, at pH7, being neither an acid nor a base, contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively. The pH scale is traceable to a set of standard solutions whose pH is established by international agreement, the pH of aqueous solutions can be measured with a glass electrode and a pH meter, or an indicator. In the first papers, the notation had the H as a subscript to the p, as so. The exact meaning of the p in pH is disputed, but according to the Carlsberg Foundation and it has also been suggested that the p stands for the German Potenz, others refer to French puissance. Another suggestion is that the p stands for the Latin terms pondus hydrogenii, potentia hydrogenii and it is also suggested that Sørensen used the letters p and q simply to label the test solution and the reference solution. Currently in chemistry, the p stands for decimal cologarithm of, PH is defined as the decimal logarithm of the reciprocal of the hydrogen ion activity, aH+, in a solution. P H = − log 10 = log 10 For example and this definition was adopted because ion-selective electrodes, which are used to measure pH, respond to activity. For H+ number of electrons transferred is one and it follows that electrode potential is proportional to pH when pH is defined in terms of activity. The reference electrode may be a silver chloride electrode or a calomel electrode, the hydrogen-ion selective electrode is a standard hydrogen electrode. Reference electrode | concentrated solution of KCl || test solution | H2 | Pt Firstly, the cell is filled with a solution of hydrogen ion activity. Then the emf, EX, of the cell containing the solution of unknown pH is measured. PH = pH + E S − E X z The difference between the two measured emf values is proportional to pH and this method of calibration avoids the need to know the standard electrode potential. The proportionality constant, 1/z is ideally equal to 12.303 R T / F the Nernstian slope, to apply this process in practice, a glass electrode is used rather than the cumbersome hydrogen electrode. A combined glass electrode has a reference electrode. It is calibrated against buffer solutions of hydrogen ion activity
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