Elements and Compounds
Step 1 - In the ionic compounds to be learnt in junior science, there are two parts to the ionic compound - the first is a positive ion (usually a metal e.g. Na 1+) and the second is a negative ion (e.g. Cl 1– ). Step 2 - Using the valency table, write the two ions and their valencies. Step 3 - Now ignore the positive and negative signs.
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CHROMIUM AND CHROMIUM COMPOUNDS
(a) Chromite ore. Chromite ore consists of varying percentages of chromium, iron, aluminium and magnesium oxides as the major components. It has been classified …
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Chrome Ore – Everything You Need to Know | SwapX
Chromium ore, otherwise known as chromite, is a mineral composed of natural oxide of ferrous iron and chromium, with varying amounts of magnesium and Aluminium substituting for the iron and chromium. This hard, brittle gray metal with both a high melting point and corrosion resistance, makes it a key element in stainless steel production.
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Toxic Mechanisms of Five Heavy Metals: Mercury, Lead, Chromium, Cadmium
Contamination of water and air by toxic metals is an environmental concern and hundreds of millions of people are being affected around the world. ... Mercury compounds have many applications in mining for example extraction of gold and some industrial processes. ... New evidence against chromium as an essential trace element. …
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Harmony to restructure Tshepong amid expected full-year losses
Harmony expects to report a loss a share of between 160c and 189c – a decrease of more than on the earnings a share of 842c reported for the 2021 financial year. Headline earnings a share ...
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The Periodic Table's Endangered Elements
Helium. Helium, being the second most abundant element in the universe, might seem an odd element to be kicking off this list of endangered elements with. The light gas has a range of uses on Earth, from helium-filled party balloons, to supercooling magnets to very low temperatures in MRI machines. The issue is that it's so light, it's able ...
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Minerals & Elements
A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. Minerals may be metallic, like gold, or nonmetallic, such as talc. Gold.
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Chrome vs. Chromium
Chrome and chromium are not the same substances, although they are related to each other. Chromium is element number 24 on the periodic table. It is a transition metal. …
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Chromite mining
The strategic mineral concept was created during World War I and became law just prior to World War II with the passage of the Strategic Minerals Act of 1939. Chromite is used …
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Chromium | ToxFAQs™ | ATSDR
Chromium is a naturally occurring element found in rocks, animals, plants, and soil. It can exist in several different forms. Depending on the form it takes, it can be a liquid, solid, or gas. The most common forms are chromium (0), chromium (III), and chromium (VI). No taste or odor is associated with chromium compounds.
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Periodic Table of Elements: Los Alamos National Laboratory
All compounds of chromium are colored. The most important chromates are those of sodium and potassium, the dichromates, and the potassium and ammonium chrome alums. The dichromates are used as oxidizing agents in quantitative analysis, also in tanning leather. Other compounds are of industrial value; lead chromate is chrome yellow, a …
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Chromium (Cr)
Chromium is mined as chromite (FeCr 2 O 4) ore. Chromium ores are mined today in South Africa, Zimbabwe, Finland, India, Kazakihstan and the Philippines. A total of 14 million …
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5.4: A Molecular View of Elements and Compounds
P 4 is a substance that is made up of four atoms of the same element, so it is a molecular element. The formula for oxygen gas is O 2 so it is a molecular element. Exercise 5.4.1 5.4. 1. Provide the classification (i.e. atomic element, molecular element, molecular compound, or ionic compound) of each substance. I 2.
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Harmony Gold's Tshepong mines steal first-quarter …
As a rand-cost producer, the gold price received continued to move in Harmony's favour, increasing 1% to R954 916/kg from R944 671/kg in the previous quarter, resulting in a 1% increase in gold ...
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Chromium (Cr)
Chromium. Chromium is a lustrous, brittle, hard metal. Its colour is silver-gray and it can be highly polished. It does not tarnish in air, when heated it borns and forms the green chromic oxide. Chromium is unstable in oxygen, it immediately produces a thin oxide layer that is impermeable to oxygen and protects the metal below.
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Chromium in Environment, Its Toxic Effect from Chromite-Mining …
The effluents and solid wastes from the mining, chrome-plating, leather-tanning, and dye-manufacturing industries are high in chromium concentration and …
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Gold, Chemical Element
A telluride is a compound of the element tellurium and one or more other elements. For example, the mineral calavarite is mostly gold telluride (AuTe 2 ). At one time, gold was found in chunks or nuggets large enough to see. People mined gold by picking it out of streams and rivers.
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Tshepong Operations | South Africa | Underground | Harmony
Tshepong Operations is an integrated, deep-level underground mining complex in the Free State, near the town of Welkom, some 250km from Johannesburg that includes the Tshepong and Phakisa underground mines/sections. These two operations were amalgamated into a single complex from FY18 and reported as Tshepong Operations.
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Chromium (III) compounds
The most stable oxidation state of the element chromium is chromium (III), found in chromite. Chromite is the most important chromium ore mined for the recovery of …
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ChemTeam: Elements and Compounds
Sodium metal (Na) and chlorine gas (formula = Cl) have very, very different properties from each other and neither one of the two is like sodium chloride at all. Compounds have names and formulas. The formula is made from the symbols of the elements in the molecule and how many of each element there are. For example, glucose's formula is C.
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Molecules and compounds overview | Atomic structure (article)
Compounds can be classified as ionic or covalent. Molecules are the simplest unit of a covalent compound, and molecules can be represented in many different ways. Atoms are the smallest units of matter that still retain the fundamental chemical properties of an element. Much of the study of chemistry, however, involves looking at what happens ...
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All the Metals We Mined in One Visualization
3,248,814,334. . Miners produced roughly three billion tonnes of iron ore in 2019, representing close to 94% of all mined metals. The primary use of all this iron is to make steel. In fact, 98% of iron ore goes into steelmaking, with the rest fulfilling various other applications. Industrial and technology metals made up the other 6% of all ...
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Discovery, properties and applications of chromium and its compounds
Naturally occurring chromium is composed of the three stable isotopes 52 Cr, 53 Cr and 54 Cr with 52 Cr being the most abundant (83.8 %). 19 radioisotopes have been characterized with the most stable being 50 Cr with a half-life of more than 1.8 × 10 17 years and 51 Cr with a half-life of 27.7 days. All of the remaining radioactive isotopes …
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12.3: Metals and Ores
Metal ores are generally oxides, sulfides, silicates (Table 12.3.1 12.3. 1) or "native" metals (such as native copper) that are not commonly concentrated in the Earth's crust, or "noble" metals (not usually forming compounds) such as gold (Figure 12.3.1 12.3. 1 ). The ores must be processed to extract the metals of interest from the waste rock ...
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Elements, compounds and mixtures
compound A pure substance made from two or more elements which are chemically bonded in a fixed ratio. and. mixtures. close. mixture When two or more compounds or elements are present without ...
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Chemical compound | Definition, Examples, & Types | Britannica
All the matter in the universe is composed of the atoms of more than 100 different chemical elements, which are found both in pure form and combined in chemical compounds.A sample of any given pure element is composed only of the atoms characteristic of that element, and the atoms of each element are unique. For example, …
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Cadmium | Uses, Properties, & Facts | Britannica
Properties, occurrence, and uses. Silver-white and capable of taking a high polish, cadmium is nearly as soft as tin and, like tin, emits a crackling sound when bent; it can be rolled out into sheets. Cadmium melts and boils at relatively low temperatures; its vapour is deep yellow and monatomic. The metal is permanent in dry air, becomes ...
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CHROMIUM AND CHROMIUM COMPOUNDS
(a) Chromite ore. Chromite ore consists of varying percentages of chromium, iron, aluminium and magnesium oxides as the major components. It has been classified into three general grades associated with their use and chromic oxide content: metallurgical (greater than 46%), chemical (40–46%) and refractory (less than 40%) grades ().During the past two …
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