Periodic Table Web Elements

1. Periodic TableWeb Elements Brennen Moores 1st Hour

2. Hydrogen • Hydrogen is the lightest element. It is by far the most abundant element in the universe and makes up about about 90% of the universe by weight. Hydrogen as water (H2O) is absolutely essential to life and it is present in all organic compounds. Hydrogen is the lightest gas. Hydrogen gas was used in lighter-than-air balloons for transport but is far too dangerous because of the fire risk (Hindenburg). It burns in air to form only water as waste product and if hydrogen could be made on sufficient scale from other than fossil fuels then there might be a possibility of a hydrogen economy. • Name: Hydrogen • Symbol: H • Atomic number: 1 • Atomic weight: 1.00794 (7) [see notes gmr] • Standard state: gas at 298 K • CAS Registry ID: 1333-74-0

3. Helium • Helium is one of the so-called noble gases. Helium gas is an unreactive, colourless, and odourless monoatomic gas. Helium is available in pressurised tanks. • Helium is the second most abundant element in the universe after hydrogen. α-particles are doubly ionised helium atoms, He2+. • Helium is used in lighter than air balloons and while heavier than hydrogen, is far safer since helium does not burn. Speaking after breathing an atmosphere rich in helium results in a squeaky voice (don't try it!). • Name: Helium • Symbol: He • Atomic number: 2 • Atomic weight: 4.002602 (2) [see notes gr] • Standard state: gas at 298 K • CAS Registry ID: 7440-59-7

4. Lithium • Lithium is a Group 1 (IA) element containing just a single valence electron (1s22s1). Group 1 elements are called "alkali metals". Lithium is a solid only about half as dense as water and lithium metal is the least dense metal. A freshly cut chunk of lithium is silvery, but tarnishes in a minute or so in air to give a grey surface. Its chemistry is dominated by its tendency to lose an electron to form Li+. It is the first element within the second period. • Lithium is mixed (alloyed) with aluminium and magnesium for light-weight alloys, and is also used in batteries, some greases, some glasses, and in medicine. • Lithium does not occur as the free metal in nature because of its high reactivity. Deposits are known all aroun the world. It is a minor component of nearly all igneous rocks and is a component of many natural brines • Name: Lithium • Symbol: Li • Atomic number: 3 • Atomic weight: [ 6.941 (2)] [see notes gmr] • Standard state: solid at 298 K • CAS Registry ID: 7439-93-2

5. Beryllium • Beryllium is a Group 2 (IIA) element. It is a metal and has a high melting point. At ordinary temperatures, beryllium resists oxidation in air. Beryllium compounds are very toxic. Its ability to scratch glass is probably due to the formation of a thin layer of the oxide. Aquamarine and emerald are precious forms of the mineral beryl, [Be3Al2(SiO3)6]. • Its chemistry is dominated by its tendency to lose an electron to form Be2+. As this ion is so small it is highly polarising, to the extent that its compounds are rather covalent. Its small size means that its complexes tend to be tetrahedral rahter than octahedral • Name: Beryllium • Symbol: Be • Atomic number: 4 • Atomic weight: 9.012182 (3) • Standard state: solid at 298 K • CAS Registry ID: 7440-41-7

6. Boron • Boron is a Group 13 element that has properties which are borderline between metals and non-metals (semimetallic). It is a semiconductor rather than a metallic conductor. Chemically it is closer to silicon than to aluminium, gallium, indium, and thallium. • Crystalline boron is inert chemically and is resistant to attack by boiling HF or HCl. When finely divided it is attacked slowly by hot concentrated nitric acid • Name: Boron • Symbol: B • Atomic number: 5 • Atomic weight: 10.811 (7) [see notes gmr] • Standard state: solid at 298 K • CAS Registry ID: 7440-42-8

7. Carbon • Carbon is a Group 14 element and is distributed very widely in nature. It is found in abundance in the sun, stars, comets, and atmospheres of most planets. • Carbon is found free in nature in three allotropic forms: amorphous, graphite, and diamond. Graphite is one of the softest known materials while diamond is one of the hardest. Carbon, as microscopic diamonds, is found in some meteorites. Natural diamonds are found in ancient volcanic "pipes" such as found in South Africa. Diamonds are also recovered from the ocean floor off thName: Carbon • Symbol: C • Atomic number: 6 • Atomic weight: 12.0107 (8) [see notes gr] • Standard state: solid at 298 K • CAS Registry ID: 7440-44-0 • e Cape of Good Hope.

8. Nitrogen • Nitrogen is a Group 15 element. Nitrogen makes up about 78% of the atmosphere by volume but the atmosphere of Mars contains less than 3% nitrogen. The element seemed so inert that Lavoisier named it azote, meaning "without life". However, its compounds are vital components of foods, fertilizers, and explosives. Nitrogen gas is colourless, odourless, and generally inert. As a liquid it is also colourless and odourless. • When nitrogen is heated, it combines directly with magnesium, lithium, or calcium. When mixed with oxygen and subjected to electric sparks, it forms nitric oxide (NO) and then the dioxide (NO2). When heated under pressure with hydrogen in the presence of a suitable catalyst , ammonia forms (Haber process). Nitrogen is "fixed" from the atmosphere by bacteria in the roots of certain plants such as clover. Hence the usefulness of clover in crop rotation • Name: Nitrogen • Symbol: N • Atomic number: 7 • Atomic weight: 14.0067 (2) [see notes gr] • Standard state: gas at 298 K • CAS Registry ID: 7727-37-9

9. Oxygen • Oxygen is a Group 16 element. While about one fifth of the atmosphere is oxygen gas, the atmosphere of Mars contains only about 0.15% oxygen. Oxygen is the third most abundant element found in the sun, and it plays a part in the carbon-nitrogen cycle, one process responsible for stellar energy production. Oxygen in excited states is responsible for the bright red and yellow-green colours of the aurora. About two thirds of the human body, and nine tenths of water, is oxygen. The gas is colourless, odourless, and tasteless. Liquid and solid oxygen are pale blue (see picture above) and stName: Oxygen • Symbol: O • Atomic number: 8 • Atomic weight: 15.9994 (3) [see notes gr] • Standard state: gas at 298 K • CAS Registry ID: 7782-44-7 • ronglyparamagnetic (contains unpaired electrons).

10. Fluorine • Fluorine is a Group 17 element. Fluorine is the most electronegative and reactive of all elements. It is a pale yellow, corrosive gas, which reacts with practically all organic and inorganic substances. Finely divided metals, glass, ceramics, carbon, and even water burn in fluorine with a bright flame. It is not uncommon to see fluorine spelled incorrectly as flourine. Name: Fluorine • Symbol: F • Atomic number: 9 • Atomic weight: 18.9984032 (5) • Standard state: gas at 298 K • CAS Registry ID: 7782-41-4

11. Neon • Neon is a very inert element. Neon forms an unstable hydrate. In a vacuum discharge tube, neon glows reddish orange. Of all the rare gases, the discharge of neon is the most intense at ordinary voltages and currents. It is present in the atmosphere as 1 part in 65000. • Liquid neon has over 40 times more refrigerating capacity than liquid helium, and more than 3 times that of liquid hydrogen. • Name: Neon • Symbol: Ne • Atomic number: 10 • Atomic weight: 20.1797 (6) [see notes gm] • Standard state: gas at 298 K • CAS Registry ID: 7440-01-9

12. Sodium • Sodium is a Group 1 element (or IA in older labelling styles). Group 1 elements are often referred to as the "alkali metals". The chemistry of sodium is dominated by the +1 ion Na+. Sodium salts impart a characteristic orange/yellow colour to flames and orange street lighting is orange because of the presence of sodium in the lamp. • Soap is generally a sodium salt of fatty acids. The importance of common salt to animal nutrition has been recognized since prehistoric times. The most common compound is sodium chloride, (table salt). • Name: Sodium • Symbol: Na • Atomic number: 11 • Atomic weight: 22.98976928 (2) • Standard state: solid at 298 K • CAS Registry ID: 7440-23-5

13. Magnesium • Magnesium is a grayish-white, fairly tough metal. Magnesium is the eighth most abundant element in the earth's crust although not found in it's elemental form. It is a Group 2 element (Group IIA in older labelling schemes). Group 2 elements are called alkaline earth metals. Magnesium metal burns with a very bright light. • Magnesium is an important element for plant and animal life. Chlorophylls are porphyrins based upon magnesium. The adult human daily requirement of magnesium is about 0.3 g day-1. • Name: Magnesium • Symbol: Mg • Atomic number: 12 • Atomic weight: 24.3050 (6) • Standard state: solid at 298 K • CAS Registry ID: 7439-95-4

14. Aluminium • Pure aluminium is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking. It is somewhat decorative. It is easily formed, machined, and cast. Pure aluminium is soft and lacks strength, but alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties. Aluminium is an abundant element in the earth's crust, but it is not found free in nature. The Bayer process is used to refine aluminium from bauxite, an aluminium ore. Name: Aluminium • Symbol: Al • Atomic number: 13 • Atomic weight: 26.9815386 (8) • Standard state: solid at 298 K • CAS Registry ID: 7429-90-5

15. Silicon • ilicon is present in the sun and stars and is a principal component of a class of meteorites known as aerolites. Silicon makes up 25.7% of the earth's crust by weight, and is the second most abundant element, exceeded only by oxygen. It is found largely as silicon oxides such as sand (silica), quartz, rock crystal, amethyst, agate, flint, jasper and opal. Silicon is found also in minerals such as asbestos, feldspar, clay and mica. • Silicon is important in plant and animal life. Diatoms in both fresh and salt water extract silica from the water to use as a component of their cell walls. Silicon is an important ingredient in steel. Silicon carbide is one of the most important abrasives. Workers in environments where silicaceous dust is breathed may develop a serious lung disease known as silicosis. • Name: Silicon • Symbol: Si • Atomic number: 14 • Atomic weight: 28.0855 (3) [see note r] • Standard state: solid at 298 K • CAS Registry ID: 7440-21-3

16. Phosphorus • Phosphorus is commonly misspelled "phosphorous". It is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm. Phosphorus exists in several allotropic forms including white (or yellow), red, and black (or violet). White phosphorus has two modifications. Ordinary phosphorus is a waxy white solid. When pure, it is colourless and transparent. It is insoluble in water, but soluble in carbon disulphide. It catches fire spontaneously in air, burning to P4O10, often misnamed as phosphorus pentoxide. When exposed to sunlight, or when heated in its own vapour to 250°C, it is converted to the red variety. This form does not ignite spontaneously and it is a little less dangerous than white phosphorus. The red modification is fairly stable and sublimes with a vapour pressure of 1 atmosphere at 417 • Name: Phosphorus • Symbol: P • Atomic number: 15 • Atomic weight: 30.973762 (2) • Standard state: solid at 298 K • CAS Registry ID: 7723-14-0°C

17. Sulfur • Sulphur (sulfur) is a pale yellow, odourless, brittle solid, which is insoluble in water but soluble in carbon disulphide. Sulphur is essential to life. It is a minor constituent of fats, body fluids, and skeletal minerals. • The spelling of sulphur is "sulfur" in the USA while sulphur is common elsewhere. IUPAC has does not have jurisdiction over language but has decided sulfur is preferred. • Sulphur is found in meteorites, volcanoes, hot springs, and as galena, gypsum, Epsom salts, and barite. It is recovered commercially from "salt domes" along the Gulf Coast of the USA. • Jupiter's moon Io owes its colours to various forms of sulphur. A dark area near the crater Aristarchus on the moon may be a sulphur deposit. Carbon disulphide, hydrogen sulphide, and sulphur dioxide should be handled extremely carefully. Hydrogen sulphide in very small concentrations can be metabolized, but in higher concentrations it can cause death quickly by respiratory paralysis. It is insidious in that it quickly deadens the sense of smell. Sulphur dioxide is a dangerous component in atmospheric air pollution and is one of the factors responsible for acid rain. • Name: Sulfur • Symbol: S • Atomic number: 16 • Atomic weight: 32.065 (5) [see notes gr] • Standard state: solid at 298 K • CAS Registry ID: 7704-34-9