MUKHLiS TANVEER JAN KURD

Chemistry With Tanveer Kurd Mastung.

Chemistry - Iron

Introduction

Iron is the most common element found in largely in outer as well inner core of the earth.

The symbol of iron is ‘Fe’ and atomic number is ‘26.’

Iron

Iron is one of the earliest known elements that is being used by human beings.

Salient Features of Iron

Following are the major features of iron −

Pure iron element is soft, ductile, and malleable.

The boiling point of iron ranges between 15330C and 24500C.

Iron easily gets attracted towards magnet.

In dry air, iron remains inactive and does not react (with air); however, in moist air, it reacts and forms rust.

Pure iron normally does not react with pure water; however, it reacts easily with ordinary of polluted water and rust forms.

Iron reacts with halogen and Sulphur to form halide and sulphide accordingly.

Occurrence of Iron

The inner and outer cores of the earth are largely made up of iron and nickel.

Most likely, iron is the most abundantly available element of the earth; however, it is the fourth most abundantly available element of the crust.

Types of Iron

Following are the major types iron −

Hematite - Fe2O3

Magnetite - Fe3O4

Siderite - FeCO3

Compounds of Iron

Following are the major compounds of iron −

Iron (II) oxide - FeO

Iron (III) chloride - FeCl3

Iron (III) oxide-hydroxide - Fe(OH)3

Iron (II) sulfide - FeS

Iron (II) chloride - FeCl2

Iron phosphate - FePO4

Ferrate (VI) - (FeO4)2-

Iron (II) acetate - Fe(C2H3O2)2

Iron (III) sulfide - Fe2S3

Iron (III) chromate - Fe2(CrO4)3

Iron (II) hydroxide - Fe(OH)2

Iron (III) acetate - C14H27Fe3O

Iron (II) oxalate - FeC2O4

Iron (II) fluride - FeF2

Uses of Iron

Among all the metals, iron is most widely used (about 90 percent of world’s total metal production).

In most of the heavy industries, iron is the most essential element.

Industries like railway, ship building, automobile, engineering construction, etc., everywhere, iron is essentially required.

Chemistry - Copper

Introduction

Copper is a soft, ductile, and malleable metal.

Copper has very high thermal and electrical conductivity.

The symbol of copper is ‘Cu’ and atomic number is ’29.’

Copper

Copper is known to people since (about) c. 8000 BC.

Copper is the first metal, which was smelted from its ore around c. 5000 BC.

Salient Features of Copper

Copper was the first metal that cast into a shape (in a mold).

Copper was the first metal that successful alloyed with another metal, e.g. copper alloyed with tin and resultantly bronze is prepared. It is done about c. 3500 BC.

First metal to be purposefully alloyed with another metal, tin, to create bronze, c. 3500 BC.

Copper has a natural reddish-orange color; it is visible once the its surface is exposed.

Copper is a very good conductor of electricity and heat.

Copper is an element of group 11 of the periodic table.

Copper normally does not react with water; however, it does react slowly with atmospheric oxygen and form a layer of brown-black copper oxide.

The brown-black copper oxide usually protects the underlying metal from further corrosion just like passivation.

Passivation is a process of use of a light coat of a protective material, such as metal oxide, which is used to create a protective shell against the corrosion.

Occurrence of Copper

Copper is commonly found in the earth’s crust.

In 1857, the largest mass of elemental copper (weighing about 420 tones) discovered. It was found on the Keweenaw Peninsula located in Michigan, US.

Alloys of Copper

The metal alloys, which have the copper as their major constituent, is known as copper alloys.

Copper alloys are highly resistant to corrosion.

The best (traditional) example of copper alloy is bronze (made by mixing tin and brass).

Following are the major alloys of copper −

Brass

Bronze

Auricupride

Chinese silver

Corinthian bronze

Electrum, Green gold

Grey gold

Niello

Panchaloha

Rose, red, and pink gold

Spangold

Shibuichi

Tibetan silver

White gold

Compounds of Copper

Following are the major compounds of the copper −

Cupric acetate - Cu(CH3COO)2

Copper(I) oxide - Cu2O

Copper(II) oxide - CuO

Copper(II) chloride - CuCl2

Dicopper chloride trihydroxide - Cu2(OH)3Cl

Copper(I) chloride - CuCl

Copper(II) nitrate - Cu(NO3)2

Copper Cyanide - CuCN

Uses of Copper

Copper is largely used in making electric wires.

Copper is used in electric motors.

Copper is used in roofing, plumbing, and in many other industries.

Copper paint is used in painting boats and many other materials.

Many of the home appliances are made up of either pure copper or its alloys.

Chemistry - Silver

Introduction

Silver is a soft, lustrous transition, and white metal.

Silver has the highest electrical and thermal conductivity; and, it has also the highest reflectivity of any metal.

Silver

The symbol of silver is ‘Ag’ and atomic number is ’47.’

Salient Features of Silver

Silver is a precious metal used since long time by human beings.

Silver is an element of group 11 of the periodic table.

Silver has an excellent white metallic luster commonly used in a high polish.

As silver has no color; therefore, it has high reflectivity (of light).

Silver has very high electrical and thermal conductivity. Its electric conductivity is the highest – higher than copper.

Among all the metals, silver also has the lowest contact resistance.

Occurrence of Silver

The metal silver is usually found in the Earth's crust in the pure form.

Silver also found as an alloy with the gold and some other metals.

Silver is also found in some minerals, such as argentite and chlorargyrite.

Silver is largely produced as a byproduct of gold, copper, zinc, lead, etc.

Alloys of Silver

Following are the major alloys of silver −

Argentium sterling silver

Britannia silver

Doré bullion

Electrum

Goloid

Platinum sterling

Sterling silver

Tibetan silver

Compounds of Silver

Following are the major compound of silver −

Silver chloride - AgCl

Silver iodide - Agl

Silver bromide - AgBr

Silver oxide - Ag2O

Silver sulfide - Ag2S

Silver fluoride - AgF

Silver cyanide - AgCN

Silver carbonate - Ag2CO3

Silver acetate - AgC2H3O2

Silver sulfate - Ag2SO4

Silver chromate - Ag2CrO4

Silver oxalate - Ag2C2O4

Silver chlorate - AgClO3

Uses of Silver

Following are the major uses of silver −

From the ancient period, silver is being used in making coins.

Silver is also used in making ornaments.

Many of the home pots and other utensils were also used to be made by silver.

Silver has also medicinal use, as it is used as an antibiotic coating in medical devices.

Because of having very high electric conductivity, silver is commonly used in some electronic devices.

Besides, silver has many other uses, such as in photography, in chemical equipment, nanoparticles, etc.

Chemistry - Gold

Introduction

Gold is a bright, reddish yellow, soft, dense, malleable, and ductile metal naturally found in the earth’s crust.

The symbol of gold is ‘Au’ and atomic number is ‘79.’

Gold

Gold is (chemically) a transition metal and belongs to group 11 of the periodic table.

Salient Features of Gold

Gold, which remains in a solid state under standard conditions, is the least reactive element.

Gold is resistant to most of the acids.

Gold does dissolve in aqua regia; aqua regia is a mixture of nitric acid and hydrochloric acid.

However, gold is insoluble in nitric acid.

Gold usually dissolves in alkaline solutions of cyanide.

Cyanide solutions are commonly used in mining and electroplating.

Gold also dissolves in mercury and forms ‘amalgam alloys.’

Gold does not react with oxygen at any temperature.

Occurrence of Gold

Gold commonly occurs as a free element i.e. in the natural form.

Gold occurs as nuggets or else found in in rocks, grains, in veins, and in some other alluvial deposits.

Gold also occurs in a solid solution forms with the native element such as silver (as electrum).

At some places, gold also naturally alloyed with copper and palladium.

Alloys of Gold

Following are the major alloys of gold −

Colored gold

Crown gold

Electrum

Rose gold

Tumbaga

White gold

Compounds of Gold

Following are the major compounds of the gold −

Gold (III) chloride - AuCl3

Gold (I) chloride - AuCl

Cyanide - CN

Chloroauric acid - HAuCl4

Gold (III) oxide - Au2O3

Gold bromide - AuBr

Aqua regia - HNO3+3HCl

Gold bromide - AuBr3

Gold (III) hydroxide - AuH3O3

Gold fluoride - AuF3

Gold (V) fluoride - AuF5

Gold sulfide - Au2S

Fulminating gold

Gold salts

Gold heptafluoride

Uses of Gold

Gold is one of the oldest elements that human being have been using for thousands of years.

As it is highly precious and provides a beautiful look, hence it is characteristically used in making ornaments.

As per the recent trend (of the world), about 50% gold is used in making jewelry, 40% used in investments, and remaining 10% is used in industry.

Chemistry - Platinum

Introduction

Platinum is a malleable, ductile, dense, and highly unreactive chemical element.

The symbol of platinum is ‘Pt’ and its atomic number is ‘78.’

Platinum

The name of platinum is derived from a Spanish term i.e. ‘platina,’ which means "little silver."

Platinum is the most precious and the rarest metal (element) on the earth.

Salient Features of Platinum

Following are the important features of the platinum −

Platinum is a silver white metal.

Platinum is an element of group 10 of the periodic table.

Platinum is one of the rarest elements in the crust of the earth.

Platinum is one of the least reactive elements.

Platinum has six natural isotopes.

Platinum is one of the most highly valuable and precious metals.

Platinum is characteristically resists corrosion in all conditions. Because of this reason, it is considered as noble metal.

Platinum is normally insoluble in nitric and hydrochloric acid, but dissolves in hot aqua regia.

After dissolving into the hot aqua regia, platinum gives aqueous chloroplatinic acid (see the image given below).

Platinum Component

Occurrence of Platinum

Platinum is commonly found as the native (natural) platinum and as alloy with the other platinum-group.

Platinum usually occurs in the ores of nickel and copper.

Platinum also occurs naturally in the alluvial sands (commonly found in rivers).

Platinum occurs with the concentration of only (about) 0.005 ppm in the Earth's crust.

Alloys of Platinum

Platinum-iridium is one of the most significant alloys of platinum.

Compounds of Platinum

Following are the major compounds of platinum −

Platinum (II) chloride - Pt Cl2

Platinum (IV) chloride - PtCl4

Adam’s catalyst - PtO2

Platinum hexafluoride - PtF6

Potassium tetrachloropla - K2PtCl4

Krogmann’s salt - K2Pt(CN)4Br

Chloroplatinic acid - H2PtCl6

Sodium hexachloropl - Na2PtCl6

Aqua regia - HNO3+3HCl

Satraplatin

Nedaplatin

Picoplatin

Uses of Platinum

Platinum is used largely for vehicle emissions control devices.

Platinum is used in petroleum refining and many other chemical productions.

Platinum is used in electronic devices, such as in hard disk (drives).

Platinum is also used in jewelry.

Apart from all these usages, platinum is also used in medicine (anti-cancer drugs), glassmaking equipment, electrodes, turbine engines, investment, etc.

Chemistry - Zinc

Introduction

In the periodic table, zinc is the first element of group 12.

The symbol of zinc is ‘Zn’ and the atomic number is ‘30.’

In terms of availability, zinc is the 24th most abundant element found in the Earth's crust and it has five stable isotopes.

Zinc

The most common zinc ore is sphalerite (zinc blende), which is a zinc sulfide mineral.

Andreas Sigismund Marggraf, the German chemist, first discovered the pure metallic zinc in 1746.

Interestingly, alchemists burned zinc in the air and form something different thing and they named that "philosopher's wool" or "white snow."

Salient Features of Zinc

Zinc’s color is bluish-white and it is lustrous and diamagnetic metal.

Zinc metal is normally hard and brittle; however, at when the temperature increases from 1000C, it becomes malleable.

When temperature increases 2100C, then the zinc metal again becomes brittle and can be pulverized easily by beating.

Zinc is a conductor of electricity.

Occurrence of Zinc

Zinc usually found in association with some other base metals such as copper and lead.

Sphalerite is a form of zinc sulfide and it is the most heavily mined ore.

Sphalerite contains about 60 to 62% zinc.

Alloys of Zinc

Following are the major alloys of zinc −

Brass

Nickel silver

German silver

Compounds of Zinc

Following are the major compounds of zinc −

Zinc oxide - ZnO

Zinc sulfide - ZnS

Zinc halides - ZnF2

Zinc nitrate - Zn(NO3)2

Zinc chlorate - Zn(ClO3)2

Zinc sulfate - ZnSO4

Zinc phosphate - Zn3(PO4)2

Zinc molybdate - ZnMoO4

Zinc chromate - ZnCrO4

Zinc arsenite - Zn(AsO2)2

Zinc acetate - Zn(O2CCH3)2

Uses of Zinc

Zinc is one of the most important elements for the public health.

Zinc is largely used as an anti-corrosion agent and coating of iron and steel materials.

Zinc is commonly used as the anode or fuel of the zinc-air battery.

Zinc oxide is extensively used as a white pigment (see the image given below) in paints.

Zinc Component

Zinc oxide is also used as a catalyst in manufacturing rubber.

Zinc is an essentially required element for our health; it is normally used as supplementary materials in the forms as zinc oxide, zinc acetate, or zinc gluconate.

Zinc is normally antioxidant material.

Zinc deficiency in human body may cause major depressive disorder.

After the bodily injury, zinc is used to speed up the healing process.

Zinc pyrithione is commonly used in shampoos to prevent the dandruff.

Chelated zinc is usually used in toothpastes and mouthwashes (liquid), as it prevents the bad breath.

Zinc also protects skin from sunburn, therefore, it is used in body lotions.

Chemistry - Mercury

Introduction

Mercury is a chemical element, which usually known as ‘quicksilver.’

Formerly, mercury was named as ‘hydrargyrum.’

The symbol of mercury is ‘Hg’ and atomic number is ‘80.’

Mercury

The red pigment vermilion is extracted by grinding either natural cinnabar or synthetic mercuric sulfide.

Salient Features of Mercury

Mercury is a heavy and silvery-white metal.

Mercury usually available in liquid state; in normal condition, it is only the few metallic element that remains in liquid state at room temperature.

Mercury is the poor conductor of heat, but it is a good conductor of the electricity.

The freezing point of mercury is −38.830C and the boiling point is 356.730C.

Mercury poisoning caused because of the ingesting any form of mercury. It is also caused by inhalation of mercury vapor.

Mercury dissolves many metals including gold and silver to form amalgams.

Occurrence of Mercury

Mercury is one of the rarest element in the earth’s crust.

The richest mercury ores carry about 2.5 percent mercury (in terms of mass).

Mercury is found either as a native (natural) element) or in corderoite, cinnabar, livingstonite, etc. minerals.

Mercury is found the region of young mountain belt; the belt that keep forcing the denser rocks to the crust of the earth. For example, volcanic region or even hot spring regions.

Alloys of Mercury

Amalgam is the major alloy of mercury.

Compounds of Mercury

Following are the major compounds of Mercury −

Mercury (II) chloride - HgCl2

Mercury (II) oxide - HgO

Mercury sulfide - HgS

Mercury (I) – chloride - Hg2Cl2

Dimethylmer - C2H6Hg

Mercury (II) nitrate - Hg(NO3)2

Mercury (II) acetate - C4H6O4Hg

Mercury (II) sulfate - HgSO4

Mercury (I) iodide - Hg2I2

Mercury selenide - HgSe

Mercury (II) fulminate - Hg(CNO)2

Mercury (II) bromide - HgBr2

Mercury (II) iodide - HgI2

Mercury (I) oxide - Hg2O

Mercury (I) fluoride - Hg2F2

Mercuric amidochloride - ClH2HgN

Diethylmercury - C4H10Hg

Sodium amalgam

Nitromersol

Uses of Mercury

Mercury is largely used in chemical industries.

Mercury is used in electrical and electronic application.

Mercury is used in the thermometers that we use to measure the temperature.

Mercury along with its compounds are commonly used in various medicines.

Chemistry - Plutonium

Introduction

Plutonium is basically an actinide metal and it appears like silvery-gray.

The element, which atomic number is ranging between 89 and 103, is known as actinide element.

The symbol of plutonium is ‘Pu’ and atomic number is ‘94.’

Plutonium

Plutonium normally possesses six allotropes.

Plutonium is named after ‘Pluto.’

Plutonium was first discovered in 1940, by a group of scientists namely Glenn T. Seaborg, Joseph W. Kennedy, Edwin M. McMillan and Arthur C. Wahl.

Salient Features of Plutonium

Plutonium is a radioactive chemical element.

Plutonium when exposed to air, it gets tarnished and when it oxidized, it forms a dull coating.

Plutonium reacts with many elements including halogens, nitrogen, carbon, silicon, and hydrogen.

Because of fission process, neutrons get released and convert uranium-238 nuclei into plutonium-239.

Plutonium-239 and plutonium-241 both are fissile, and hence, they can sustain a nuclear chain reaction. It is very well applicable in nuclear weapons and nuclear reactors.

The melting point of plutonium is 640 0C and its boiling point is 3,228 0C.

The release of helium nucleus (a high-energy) is the most common form of radioactive decay for the plutonium.

Occurrence of Plutonium

The plutonium naturally found only in trace amounts within the uranium deposits.

Plutonium is also extracted by burning the uranium (while developing nuclear energy).

Alloys of Plutonium

Following are the major alloys of plutonium −

Plutonium–gallium is one of the important alloys of plutonium as well as of gallium.

Plutonium–gallium is used in the nuclear weapon pits.

Plutonium–gallium has the property of very low thermal expansion.

Some other alloys of plutonium are −

Plutonium–aluminum

Plutonium–gallium–cobalt

Plutonium–zirconium

Plutonium–cerium

Plutonium–uranium

Plutonium–uranium–titanium

Thorium–uranium–plutonium

Compounds of Plutonium

Plutonium (IV) oxide - PuO2

Plutonium (III) chloride - PuCl3

Plutonium tetrafluoride - PuF4

Plutonium (III) fluoride

Plutonium hexafluoride

Plutonium hydride

Plutonium carbide

Plutonium borides

Uses of Plutonium

The isotope plutonium-239 is one of the significant elements in developing the nuclear weapons.

Plutonium is used as a fuel in the nuclear power plants.

Chemistry - Uranium

Introduction

Uranium is the metal of the actinide series of the periodic table.

The symbol of uranium is ‘U’ and atomic number is ’92.’

Uranium

In 1789, Martin Heinrich Klaproth had discovered the element uranium and named it after the name of Uranus.

Salient Features of Uranium

Uranium is a silvery-white metal.

A uranium atom has 92 electrons as well as 92 protons, of which 6 are valence electrons.

Because of having unstable isotopes, uranium is a weak radioactive element.

Uranium-238 is the most common isotope of uranium.

Uranium occurs naturally in very low concentrations i.e. a few parts per million in rock, soil, and water.

Uranium decays gradually (slowly) by emitting its alpha particle.

Uranium has poor electric conductivity (so poor conductor of electricity).

Uranium is malleable, ductile, and marginally paramagnetic

Occurrence of Uranium

Uranium is (naturally) found as uranium-238, uranium-235, and uranium-234.

The half-life of uranium-238 is about 4.47 billion years almost the age of the Earth and the half-life of uranium-235 is about 704 million years.

Alloys of Uranium

Following are the major alloys of Uranium −

Staballoy

Uranium hydride

Compounds of Uranium

Following are the major compounds of Uranium −

Uranium nitride - U2N3

Uranium pentafluoride - UF5

Uranium carbide - UC

Uranyl fluoride - UO2F2

Uranium dioxide - UO2

Uranium hexafluoride - UF6

Triuranium oxtoxide - U3O8

Uranium tetrafluoride - UF4

Uranium trioxide - UO3

Uranium tetrachloride - Ucl4

Uranyl nitrate - UO2(NO3)2

Uranyl

Uraninite

Ammonium diuranate

Hexafluoride

Uranium hexachloride

Uranium (III) iodide

Uranyl acetate

Uses of Uranium

Uranium is used as power source in nuclear submarines (especially by military).

Uranium is used in making nuclear weapons.

Uranium is also used as ballasts for ships.

Chemistry - Lead

Introduction

Lead is a heavy chemical element (metal) i.e. it has high density.

The symbol of lead is ‘Pb’ and atomic number is ‘82.’

Lead

Lead has tendency to bond itself; likewise, it can form chains, bonds, rings, and polyhedral structures.

Salient Features of Lead

Lead is soft and malleable metal; it has relatively low melting point.

Lead is relatively unreactive element and it has tendency to form covenant bond.

When lead is cut, it appears bluish-white tint.

While burning, lead gives a bluish-white flame (see the image given below).

Lead Component

Compounds of lead are typically found in the +2 oxidation state.

Occurrence of Lead

Lead is known to the prehistoric people of Western Asia.

Lead is found in the earth’s crust; it is rarely found deep of the earth.

Lead is usually found in combination with sulfur.

Galena is the main lead-bearing mineral, mostly found with zinc ores.

Alloys of Lead

Following are the major alloys of lead −

Molybdochalkos (copper)

Solder (tin)

Terne (tin)

Compounds of Lead

Following are the major compounds of lead −

Lead monoxide - PbO

Lead dioxide - PbO2

Uses of Lead

Lead has been used in making bullets for hundreds of years.

Lead is commonly used as a protective sheath for the underwater cables (only because it has the property of corrosion resistance).

Lead sheets are also used as architectural metals especially in roofing material.

Lead is also used in acid batteries.

Lead compounds are commonly as coloring agents and semiconductors.

Lead compounds are also used in plastic, candles, glass, etc.

Lead is commonly used in the polyvinyl chloride (i.e. used in coating of electrical cords).

Pre-caution

Presence of lead (in excessive quality) in the body may cause severe damage to the brain and kidneys; it may even cause death lastly.

Chemistry - Thorium

Introduction

Thorium is one of the radioactive actinide metals that occur naturally in large quantities.

The symbol of thorium is ‘Th’ and atomic number is ’90.’

Thorium

In 1829, a Norwegian mineralogist Morten Thrane Esmark, first discovered thorium.

Jöns Jacob Berzelius, the Swedish chemist, identified and named it ‘thorium’ after the name of ‘Thor’, the Norse god of thunder.

Salient Features of Thorium

Thorium is paramagnetic and soft radioactive actinide metal.

Thorium metal’s color is silvery; when it exposed to air, it tarnishes black and form dioxide.

All isotopes of thorium are unstable and it is a weak radioactive element.

Among all the significant radioactive elements, the half-life of thorium is the longest, i.e. about 14.05 billion years.

The melting point of thorium is about 17500C.

Occurrence of Thorium

Thorium is primordial element that exists existed in its current form since before the Earth was formed.

Thorium, found in the earth’s crust, is refined from the monazite sands.

Monazite that occurs in large amounts across the world is the most important source of thorium.

Alloys of Thorium

Mag-Thor and thorium-aluminum are the most significant alloys of thorium, Magnesium, and aluminum.

Compounds of Thorium

Following are the major compounds of Thorium −

Thorium dioxide - ThO2

Thorium (IV) sulfide - ThS2

Thorium (IV) iodide - ThI4

Thorium tetrafluoride - ThF4

Thorium (IV chloride - ThCl4

Thorium (IV) carbide - ThC

Some others are −

Thorite

Thorium (IV) nitrate

Thorium (IV) orthosilicate

Uses of Thorium

Thorium is normally used in gas tungsten arc welding (GTAW) because it (thorium) increases the high-temperature strength of tungsten electrodes and accordingly improve arc stability.

In electronic equipment, the application of thorium coating on tungsten wire, increases the electron emission of heated cathodes.

In chemical industry, the dioxide of thorium namely ‘thoria’ is commonly used.

Chemistry - Hydrogen

Introduction

In the periodic table, hydrogen is the lightest element, its atomic weight is merely 1.008.

The symbol of hydrogen is ‘H’ and the atomic number is ‘1.’

Hydrogen

In the early 16th century, hydrogen gas was first artificially produced by the reaction of acids and metals.

Henry Cavendish first recognized the hydrogen gas a discrete substance during the period of 1766-81, as it produces water when it is burned.

Salient Features of Hydrogen

In their plasma state, the non-remnant stars are primarily composed of hydrogen.

At standard temperature and pressure, hydrogen appears colorless, tasteless, odorless, nonmetallic, non-toxic, and highly combustible diatomic gas.

The molecular formula of hydrogen is H2.

On the earth, hydrogen exists in molecular forms, for example, water or other organic compounds.

Hydrogen also plays an important role in acid–base reactions.

Hydrogen gas is highly flammable in the air.

Pure hydrogen-oxygen flames radiate ultraviolet light; further, with high oxygen mix are nearly invisible to the naked eye.

Hydrogen can react with almost every oxidizing element.

At room temperature, Hydrogen normally reacts spontaneously and viciously with chlorine and fluorine and forms the corresponding hydrogen halides.

Occurrence of Hydrogen

Consisting roughly about 75 percent of all baryonic mass, hydrogen is the most abundantly found chemical subsistence in the universe.

Throughout the universe, hydrogen is typically found in the atomic and plasma states; however, the properties quite different from those of the molecular hydrogen.

On the earth, hydrogen exists as the diatomic gas, i.e. H2.

Because of having light weight, hydrogen easily escapes from the earth’s atmosphere.

Hydrogen is the third most abundant element found on the Earth's surface, but largely found in form of hydrocarbons and water.

Compounds of Hydrogen

Following are the major compounds of hydrogen −

Water - H2O

Ammonia - NH3

Hydrogen chloride - HCl

Hydrogen fluoride - HF

Hydrogen sulfide - H2S

Methane - CH4

Hydroxide - OH-

Hydrogen bromide - HBr

Hydrogen iodide - HI

Hydrogen cyanide - HCN

Phosphine - PH3

Hydrogen selenide - H2Se

Methanol - CH3OH

Lithium hydride - LiH

Bicarbonate - HCO3

Hydrogen telluride - H2Te

Liquid hydrogen - H2

Cyanide - CN

Calcium hydride - CaH2

Heavy water - D2O

Diborane - B2H6

Sodium hydride - NaH

Potassium hydride - KH

Uses of Hydrogen

The largest amount of H2 is used in the processing of fossil fuels as well as in the production of ammonia.

Hydrogen (H2) is extensively used in the petroleum and chemical industries.

H2 is typically used as a hydrogenating agent, especially in increasing the saturation level of unsaturated fats and oils.

H2 is also used as a shielding gas in welding procedures, such as atomic hydrogen welding, etc.

Chemistry - Helium

Introduction

Helium is the second lightest (after hydrogen) and second most abundant element in the universe.

The symbol of Helium is ‘He’ and atomic number is ‘2.’

Helium

In the periodic table, Helium is the first in the noble gas group.

Helium is named after the name of the Greek god of the Sun, ‘Helios.’

Salient Features of Helium

Helium is a colorless, odorless, tasteless, inert, non-toxic, and monatomic gas.

The boiling point (-268.90C) of helium is the lowest among all the elements.

Helium is typically composed of two electrons in atomic orbitals and surrounded by a nucleus.

Occurrence of Helium

Most helium found in the universe belong to helium-4, and it is believed to have been formed during the Big Bang.

Major share of new helium is typically being created by nuclear fusion of hydrogen in stars including the Sun.

Though there is continuous creation of new helium;

In the earth’s crust, helium is characteristically found in large amounts in the minerals of uranium and thorium.

Compounds of Helium

Following are the major compounds of helium −

Disodium helide - Na2He

Cristobalite He II (Silicates) - SiO2He

Dihelium arsenolite - As4O6•2He

Isotopes of Helium

There are about nine known isotopes of helium, but following two are the most stable isotopes −

Helium-3 and

Helium-4

Uses of Helium

Because of having low density, low boiling point, low solubility, high thermal conductivity, helium is widely used element; the most popular example is – use of helium in balloon.

Helium is also used as a protective gas in growing silicon and germanium crystals.

Helium is used in supersonic wind tunnels.

Helium is also applied as a shielding gas in an arc welding processes.

Chemistry - Oxygen

Introduction

Oxygen is the member of group 16 on the periodic table; however, most of the time, it is treated differently from its group.

The symbol of oxygen is ‘O’ and atomic number is ‘8.’

Oxygen

Oxygen has about nine allotropes and the most common allotrope is diatomic oxygen (i.e. O2). Other important allotrope is Ozone i.e. O3.

Oxygen, first time, was noticed by Swedish pharmacist Carl Wilhelm Scheele.

The word "chalcogen" is derived from a Greek word “khalkόs,” which means “copper” and the Latin-Greek word “Genēs,” which means born or produced.

Oxygen is a highly reactive gas (or nonmetallic element); hence, it is an oxidizing agent that readily forms oxides with most of the elements and compounds.

Oxygen has six valence electrons.

The melting point of oxygen is -218.80C and the boiling point is -1830C.

Occurrence of Oxygen

With about 20.8 percent share (in total earth’s atmospheric constituents), oxygen is the second ranked element of the earth’s atmosphere.

Oxygen occurs almost in sphere of the earth namely atmosphere, hydrosphere, and lithosphere.

Oxygen occurs as constituent copper ores.

A human body contains about 65 percent oxygen.

By mass, almost half of the earth’s crust is composed of oxygen (i.e. its oxides).

By mass, oxygen is the third-most abundant element that found in the universe; the first and second are hydrogen and helium accordingly.

Oxygen (i.e. O2) is a colorless and odorless diatomic gas.

Compounds of Oxygen

Following are the major compounds of oxygen −

Oxide

Peroxide

Carbon dioxide - CO2

Hydroxide - OH-

Ozone - O3

Mercury (II) oxide - HgO

Chlorate - ClO3

Aluminum oxide - Al2O3

Carbon monoxide - CO

Hypochlorite - ClO-

Silicon dioxide - SiO2

Hypofluorous acid - HOF

Sodium peroxide - Na2O2

Potassium chlorate - KClO3

Oxygen difluoride - OF2

Sodium oxide - Na2O

Uses of Oxygen

Oxygen (O2) is the most essential requirements for the respiration, without it, life cannot be imagined.

Oxygen is used in medicine.

Oxygen therapy is typically used to treat some diseases, such as, emphysema, pneumonia, some heart disorders, etc.

Some of the underwater activities, such as scuba diving, submarines, etc. also use artificial oxygen.

Artificial Oxygen.

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