2P2 32 Zhou Jinquan

Carbon Monoxide:


Made of: Carbon and oxygen
Formula: CO

Carbon Dioxide
Carbon is a naturally abundant nonmetallic element which forms the basis of most living organisms. Carbon is the fourth most abundant element in the universe, and it plays a crucial role in the health and stability of the planet through the carbon cycle. This cycle is extremely complex, and it illustrates the interconnection between organisms on Earth. Most consumers are familiar with the element, along with numerous forms in which it appears.


The atomic number of carbon is six, and the element is identified by the symbol “C” on the periodic table. The structure ofcarbon molecules is such that the molecules bond readily with a wide range of other elements, forming thousands of compounds. The molecules in carbon also bond with each other in different ways, creating forms of carbon such as diamonds, the hardest substance on Earth, and graphite, one of the softest materials on the planet. The changing personality of carbon, depending on what it bonds with and how, makes it a very unique element.


All living organisms contain carbon, and as they decay or change, they will continue to contain the element. Coal, limestone, and petroleum, for example, are all fossilized forms of living organisms containing abundant amounts of carbon. Plants and animal life which died millions of years ago were slowly compressed into these substances, and their integral carbon was preserved.


Oxygen

Name: Oxygen	Symbol: O
Type: Non-Metal, Chalcogen	Atomic weight: 15.9994
Density @ 293 K: 0.001429 g/cm3	Atomic volume: 14.0 cm3/mol

Oxygen is needed for all living things and ait is also vital for the process of producing water.

Formation:


Its chemical bonding requires covalent bonding.Carbon monoxide is formed by combustion of carbon in oxygen at high temperatures when there is an excess of carbon. It is also formed (with oxygen) by decomposition of carbon dioxide at very high temperatures (above 2,000°C). It is present in the exhaust of internal-combustion engines (e.g., in automobiles) and is generated in coal stoves, furnaces, and gas appliances that do not get enough air. Carbon monoxide is also a constituent of tobacco smoke.

Credits:

Wikipedia

http://answers.encyclopedia.com/question/carbon-monoxide-formed-114489.html

Sorry, Mrs Chu, I am a bit late as I have to rush to MOELC at Bishan Thank you for your understanding!

Yi En Index 13

Carbon Monoxide

Covalent bond

The name for Carbon Monoxide is CO, C being Carbon and O being Oxygen. Both Carbon and Oxygen are harmless (not harmful) as we can see from oxygen being breathed in everyday life. Carbon and Oxygen bond by covalent bonding. This means that they bond by sharing their electrons with one another. It consists of one carbon atom and one oxygen atom, connected by a triple bond which consists of two covalent bonds as well as one dative covalent bond. 

Carbon monoxide  forms when there is not enough oxygen to produce carbon dioxide (CO2), such as when operating a stove or an internal combustion engine in an enclosed space. In the presence of oxygen, carbon monoxide burns with a blue flame, producing carbon dioxide. Coal gas, which was widely used before the 1960s for domestic lighting, cooking and heating, had carbon monoxide as a significant constituent. Some processes in modern technology, such as iron smelting, still produce carbon monoxide as a byproduct.    

               

Cao Yang Eric (2)

Dihydrogen Monoxide
Symbol: H2O
Dihydrogen Monoxide contains 2 atoms of hydrogen and 1 atom of  oxygen.
Chemical Bond
It is a convalent bond.

Harmful Effects
Dihydrogen monoxide:
• is also known as hydroxl acid and is the major component of acid rain. 
• contributes to the "greenhouse effect." 
• may cause severe burns. 
• contributes to the erosion of our natural landscape. 
• accelerates corrosion and rusting of many metals. 
• may cause electrical failures and decreased effectiveness of automobile brakes. 
• has been found in excised tumors of terminal cancer patients. 

Constituent Elements
Hydrogen:
Symbol: H
Atomic Number: 1
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weightof 1.00794 u (1.007825 u for Hydrogen-1), hydrogen is the lightest and most abundant chemical element, constituting roughly 75 % of the Universe's chemical elemental mass. Stars in the main sequence are mainly composed of hydrogen in its plasma state. Naturally occurring elemental hydrogen is relatively rare on Earth.

Oxygen:
Symbol: O
Atomic Number: 8
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots.It was mistakenly thought that all acids required oxygen in their composition. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless, odorless, tasteless diatomic gas with the formula O₂.

2P2 28 Wang Jiaxin

Ammonium
The ammonium (more obscurely: aminium) cation is a positively charged polyatomic cation with the chemical formula NH+
4. It is formed by the protonation of ammonia (NH₃). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (N⁺R₄), where one or more hydrogen atoms are replaced by organic radical groups (indicated by R).
In the substitutive nomenclature NH₄⁺ is denoted by the name azanium instead of ammonium.
Formation
Formation of ammonium compounds can also occur in the vapor phase; for example, when ammonia vapor comes in contact with hydrogen chloride vapor, a white cloud of ammonium chloride forms, which eventually settles out as a solid in a thin white layer on surfaces.
The conversion of ammonium back to ammonia is easily accomplished by the addition of strong base.

Carbon-nitrogen bond

A carbon-nitrogen bond is a covalent bond between carbon and nitrogen and is one of the most abundant bonds in organic chemistry and biochemistry.^[1]
Nitrogen has five valence electrons and in simple amines it is trivalent, with the two remaining electrons forming a lone pair. Through that pair, nitrogen can form an additional bond to hydrogen making it tetravalent and with a positive charge in ammonium salts. Many nitrogen compounds can thus be potentially basic but its degree depends on the configuration: the nitrogen atom in amides is not basic due to delocalization of the lone pair into a double bond and in pyrrole the lone pair is part of an aromatic sextet.
Similar to carbon-carbon bonds, these bonds can form stable double bonds, for instance imines and triple bonds such as nitriles. Bond lengths range from 147.9 pm for simple amines to 147.5 pm for C-N= compounds such as nitromethane to 135.2 pm for partial double bonds in pyridine to 115.8 pm for triple bonds as in nitriles.
A CN bond is strongly polarized towards nitrogen (electronegativity for C and N is 2.55 and 3.04, respectively) and subsequently molecular dipole moments can be high: cyanamide 4.27 D, diazomethane 1.5 D, methyl azide 2.17, pyridine 2.19. For this reason many compounds containing CN bonds are water-soluble.

Properties of Carbon
Carbon  is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with ¹²C and ¹³C being stable, while ¹⁴C is radioactive, decaying with a half-life of about 5730 years. Carbon is one of the few elements known since antiquity. The name "carbon" comes from Latin carbo, coal.

Properties of Nitrogen 

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772.

2P205 Dai Nan Tian

Harmful Compound: Carbon Monoxide

Made from: Carbon and Oxygen  

Symbol: CO

Chemical Bonding: Covalent bonding

Harmful Effects- Once carbon monoxide is inhaled, it will rapidly accumulate in the blood and deplete its ability to carry oxygen throughout the body. Depending on the amount of CO inhaled, the significant harmful effects caused by this gas can lead to carbon monoxide poisoning.

This is the amount that cause different effects

·         10% COHb - No symptoms. Heavy smokers can have as much as 9% COHb.

·         15% COHb - Mild headache.

·         25% COHb - Nausea and serious headache. Fairly quick recovery after treatment with oxygen and/or fresh air.

·         30% COHb - Symptoms intensify. Potential for long term effects especially in the case of infants, children, the elderly, victims of heart disease and pregnant women.

·         45% COHb - Unconsciousness

·         50+% COHb – Death

Constituent elements of Carbon Monoxide:

Carbon- with C as its symbol, is an element in the 2^nd Period and Group IV. It has 6 Protons, Neutrons and Electrons. There are three naturally occurring isotopes for Carbon, with C12 and C13 being stable, while C14 is radioactive. There are several allotropes, which is types of carbon of which the best known are graphite, diamond, and amorphous carbon. The physical properties of carbon vary widely with the allotropic form. For example, diamond is highly transparent, while graphite is opaque and black. Diamond is among the hardest materials known, while graphite is soft enough to form a streak on paper. Diamond has a very low electrical conductivity, while graphite is a very good conductor. Under normal conditions, diamond has the highest thermal conductivity of all known materials. All the allotropic forms are solids under normal conditions but graphite is the most thermodynamically stable. Carbon is the fourth most abundant chemical element in the universe by mass after hydrogen, helium, and oxygen. Carbon is abundant in the Sun, stars, comets, and in the atmospheres of most planets.

Oxygen- is a colorless, odorless, tasteless gaseous chemical  element which appears in great abundance on Earth, trapped by  the atmosphere. It is a vital component of the respiration process; without oxygen,  most organisms will die  within minutes. A number of forms of oxygen  and oxygen compounds can be found in nature. Oxygen can also be isolated and sold in pure  form for an assortment of uses, and was first isolated and identified in 1774. The atomic number of oxygen is eight,  and it is identified by an O symbol   on the periodic table of elements.  In addition to being very widely distributed on Earth, oxygen is also the third most abundant  element in the universe, and  it is a key catalyst in many chemical reactions. Oxidation is one such reaction, and it occurs  when oxygen mixes  with other elements and compounds. Oxygen also plays a role in combustion. Formation It is formed when one carbon atom and one oxygen atom,  connected by a triple bond which consists of two covalent bonds as well as one dative covalent bond. It is the simplest  of carbon, and is an anhydride of formic acid. In coordination complexes the carbon monoxide ligand is called carbonyl.

 The "Dot and Cross" diagram

2P216 Jerrick Lim (16)

Nitrogen Dioxide NO_{2
It is made from nitrogen and oxygen.}

Chemical bonding
Convalent bonding

Constituent elements

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass of 14.00674 u. Elemental nitrogen is a colourless, odourless and tasteless gas at standard conditions. It also constitutes 78.08% by volume of Earth's atmosphere.

Oxygen

Oxygen is a colourless, odourless, tasteless and combustible gaseous chemical element which appears in great abundance on Earth, trapped by the atmosphere. Also, it is an important  component during the respiration process because without oxygen, most organisms will die within minutes. Oxygen can also be isolated and sold in pure form for an assortment of uses, an was first isolated and identified in 1774. The atomic number of oxygen is eight, and it's symbol is O on the periodic table of elements. Oxygen is also the third most abundant element in the universe, and it is a key catalyst in many chemical reactions. Oxidation is one such reaction, and it occurs when oxygen mixes with other elements and compounds. 

 Formation

The most important forms of reactive nitrogen in the air are nitrogen monoxide (NO) and nitrogen dioxide (NO₂) and together we call them NOx.  Nitrogen oxides are formed in the atmosphere mainly from the breakdown of nitrogen gas (N₂).  Because the two nitrogen atoms in N₂ are bound very strongly together (with a nitrogen to nitrogen triple bond), it isn't easy to break N₂down into its atoms.  A few bacteria have developed special mechanisms to do this and very high temperatures can also break the molecule down.  Vehicle engines operate at high enough temperatures and nitrogen oxides are emitted in the exhaust fumes.  Catalytic converters fitted to cars decrease the production of these harmful compounds.  Nitrogen oxides can also be formed when biomass is burnt and during lightning.

Dot diagram

Timothy Chng (04) 10th February

Chemical: Toluene

Chemical Formula: C₆H₅H + CH₃⁺ + AlCl₄^- → C₆H₅CH₃ + HCl + AlCl₃
Bond: Covalent bonding is present in toluene

Benzene reacts with methyl chloride in presence of anhydrous aluminium chloride to form toluene. The formation follows an electrophilic substitution reaction mechanism. Benzene is a colorless and highly flammable liquid with a sweet smell. It is an important industrial solvent and precursor in the production of drugs, plastics, synthetic rubber, and dyes. Benzene is a natural constituent of crude oil, and may be synthesized from other compounds present in petroleum. Anhydrous aluminium chloride is a powerful Lewis acid, capable of forming Lewis acid-base adducts with even weak Lewis bases such as benzophenone and mesitylene. It forms tetrachloroaluminate AlCl₄⁻ in the presence of chloride ions. Methyl chloride is a chemical compound of the group of organic compounds called haloalkanes. It was once widely used as a refrigerant. It is a colorless extremely flammable gas with a minorly sweet odor, which is, however, detected at possibly toxic levels. Due to concerns about its toxicity, it is no longer present in consumer products.

Dickson Lim (14)

Potassium Chloride

Made of:  potassium and chlorine

Symbol: KCl

Chemical Bonding: Ionic bonding

Harmful effects

The most common side effect associated with potassium chloride is gastrointestinal distress, according to the Linus Pauling Institute at Oregon State University. This can include stomach pain, nausea, vomiting, gas and diarrhea. Rarely, potassium chloride tablets can cause intestinal ulcers.

Potassium

Atomic Number:19

Atomic Symbol: K

The greatest demand for potash has been in its use for fertilizers. Potassium is an essential constituent for plant growth and is found in most soils.

An alloy of sodium and potassium (NaK) is used as a heat-transfer medium. Many potassium salts are of utmost importance, including the hydroxide, nitrate, carbonate, chloride, chlorate, bromide, iodide, cyanide, sulfate, chromate, and dichromate.

It is one of the most reactive and electropositive of metals. Except for lithium, it is the lightest known metal. It is soft, easily cut with a knife, and is silvery in appearance immediately after a fresh surface is exposed. It rapidly oxidizes in air and must be preserved in a mineral oil such as kerosene.

As with other metals of the alkali group, it decomposes in water with the evolution of hydrogen. It catches fire spontaneously on water. Potassium and its salts impart a violet color to flames.

Chlorine

Atomic number: 17

Atomic Symbol:Cl

Chlorine is widely used in making many everyday products. It is used for producing safe drinking water the world over. Even the smallest water supplies are now usually chlorinated.

It is also extensively used in the production of paper products, dyestuffs, textiles, petroleum products, medicines, antiseptics, insecticides, food, solvents, paints, plastics, and many other consumer products.

Most of the chlorine produced is used in the manufacture of chlorinated compounds for sanitation, pulp bleaching, disinfectants, and textile processing. Further use is in the manufacture of chlorates, chloroform, carbon tetrachloride, and in the extraction of bromine.

Chlorine is a respiratory irritant. The gas irritates the mucus membranes and the liquid burns the skin. As little as 3.5 ppm can be detected as an odor, and 1000 ppm is likely to be fatal after a few deep breaths. In fact, chlorine was used as a war gas in 1915.

Lim Jing Kai 2p2(15)

Silver Iodide:
Silver Iodide is ais a yellow, inorganic, photosensitive iodide of silver used in Photography, in medicine as an antiseptic, and in rainmaking for cloud seeding. It is very insoluble in water. It is made of 1 silver element and 1 iodine element.


Chemical Bonding:
It is a ionic bond.


Harmful effects:
Although silver iodide has many good uses like rainmaking, as antiseptic, it also has many harmful effects. Silver iodide is considered a hazardous substance, a priority pollutant, and a toxic pollutant. Chronic ingestion of iodides may produce “iodism”, which may be manifested by skin rash, running nose, headache, irritation of the mucous membranes, weakness, anemia, loss of weight and general depression. Chronic inhalation, ingestion or skin contact with silver compounds may cause argyria characterized by blue-gray discoloration of the eyes, skin and mucous membranes.


Constituent Elements:
Silver: Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a by-product of copper, gold, lead, and zinc refining.

Silver has long been valued as a precious metal, and it is used to make ornaments, jewelry, high-value tableware, utensils (hence the term silverware), and currency coins. Today, silver metal is also used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions. Its compounds are used in photographic film and dilute silver nitrate solutions and other silver compounds are used as disinfectants and microbiocides. While many medical antimicrobial uses of silver have been supplanted by antibiotics, further research into clinical potential continues.

Iodine: Iodine is a chemical element that has the symbol I and the atomic number 53.

Iodine and its compounds are primarily used in nutrition, the production of acetic acid and polymers. Iodine's relatively high atomic number, low toxicity, and ease of attachment to organic compounds have made it a part of many X-ray contrast materials in modern medicine.

Like the other halogens, iodine occurs mainly as a diatomic molecule I2, not the atom. In nature, iodine is a relatively rare element, ranking 47th in abundance. It is the heaviest essential element utilized in biological functions. Its rarity in many soils has led to many deficiency problems in land animals and inland human populations, with iodine deficiency affecting about two billion people and being the leading preventable cause of mental retardation. As a component of thyroid hormones, iodine is required by higher animals. Radioisotopes of iodine are concentrated in the thyroid gland. This property of thyroid-concentration, along with its mode of beta decay, makes iodine-131 one of the most carcinogenic nuclear fission products.

Formation: Silver: 2.8.18.18.1

                 Iodine: 2.8.18.18.7

Silver iodide is formed when silver gives 1 element on its outer shell to Iodine. So silver becomes 2.8.18.18 and iodine becomes 2.8.18.18.8

Raymond Chang (22)

Diethylene glycol

It is made of 2 Hydrogen, 3 Oxygen, 4 Carbon, 4 Hydrogen Gas atoms.

Chemical Bonding

Covalent bond

Harmful Effects

Minimum toxic dose is estimated at 0.14 mg/kg of body weight and lethal dose between 1 and 1.63 g/kg of body weight.

Nausea, vomiting, abdominal pain, and diarrhoea,

Metabolic acidosis, which causes acute kidney failure, oliguria, increasing serum creatinine concentrations.

Progressive lethargy, facial paralysis, dysphonia, dilated and nonreactive pupils, quadriplegia, and coma leading to death.

Constituent elements

Oxygen

Oxygen is a colourless, odourless, tasteless gaseous chemical element which appears in great abundance on Earth, trapped by the atmosphere. Many people are familiar with oxygen, because it is a vital component of the respiration process; without oxygen, most organisms will die within minutes. A number of forms of oxygen andoxygen compounds can be found in nature. Oxygen can also be isolated and sold in pure form for an assortment of uses, and was first isolated and identified in 1774.

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.

Hydrogen gas

Hydrogen gas (now known to be H₂) was first artificially produced in the early 16th century, via the mixing of metals with strong acids. In 1766–81, Henry Cavendish was the first to recognize that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name, which in Greek means "water-former." At standard temperature and pressure, hydrogen is a colourless, odourless, non-metallic, tasteless, highly combustible diatomic gas with the molecular formula H₂.

Carbon

Carbon, with C as its symbol, is an element in the 2^nd Period and Group IV. It has 6 Protons, Neutrons and Electrons. There are three naturally occurring isotopes for Carbon, with C12 and C13 being stable, while C14 is radioactive. There are several allotropes, which is types of carbon of which the best known are graphite, diamond, and amorphous carbon. The physical properties of carbon vary widely with the allotropic form. For example, diamond is highly transparent, while graphite is opaque and black. Diamond is among the hardest materials known, while graphite is soft enough to form a streak on paper. Diamond has a very low electrical conductivity, while graphite is a very good conductor. Under normal conditions, diamond has the highest thermal conductivity of all known materials. All the allotropic forms are solids under normal conditions but graphite is the most thermodynamically stable. Carbon is the fourth most abundant chemical element in the universe by mass after hydrogen, helium, and oxygen. Carbon is abundant in the Sun, stars, comets, and in the atmospheres of most planets.

Tan Yew Jie (25)

Potassium Cyanide KCN

Made up of 1 Potassium atom, 1 Carbon atom and 1 Nitrogen atom.

Chemical Bonding

It is a Ionic Bond.

Harmful Effects

This prevents the body from oxidizing food to produce useful energy. Initially, acute cyanide poisoning causes a red or ruddy complexion in the victim because the tissues are not able to use the oxygen in the blood. The person may die within 45 minutes if not treated medically. During this period, convulsions may occur. Death occurs mainly by cardiac arrest. A number of prominent persons were killed or committed suicide using potassium cyanide.

Constituent Elements
Potassium (K)

Potassium is the chemical element with the symbol K, atomic number 19, and atomic mass 39.0983. Elemental potassium is a soft silvery-white metallic alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.

Carbon (C)

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with ¹²C and ¹³C being stable, while ¹⁴C is radioactive, decaying with a half-life of about 5730 years.^[9] Carbon is one of the few elements known since antiquity. The name "carbon" comes from Latin carbo, coal.

Nitrogen (N)

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772.

Formation

Potassium (K) has 19 valance electrons. Carbon (C) has 6 valance electrons. Nitrogen (N) has 7 valance electrons.

Gareth Lim Zhi Yang (07)

Sulphuric Acid 


Molecular Formula: H2SO4


Harmful effects: 


Towards humans 

•  It is corrosive so it will cause burns to any contacted area and may cause blindness if contacted with the eye, long exposure to the acid in vapour form may cause cancer and possibly death if ingested.

Towards environment (Makes rain acidic as sulphur dioxide from factories dissolves in the rain)

•  Kills or harms plants due to low PH (unfavourable environment)
•  Kills or harms organism living in water bodies (lower PH of water, making it an unsuitable environment for many of those organisms)
   Therefore, affecting the ecosystem

Others

•  Eat away buildings (acid rain)

                      


Chemical bonding involved: Covalent bond (SO₄ is made up of 2
non-metal elements) and ionic bond ([SO₄]^- is a non-metal ion as it is a anion while H⁺ is a metal ion as it is a cation)


Constituent elements: Sulphur (S), Hydrogen (H) & Oxygen (O)

• Sulphur: Sulphur is an odorless, tasteless, light yellow solid (in room temperature) which belongs to group VII of  the periodic table, has an atomic number of 16 and a nucleon number of 32 (Most common isotope) . Sulphur has a melting/freezing point of 115.2 °C and a boiling point of 444.6 °C and usually comes in the form of a yellow coloured powder/stone. Sulphur has 5 stable isotopes, ³²S, ³³S, ³⁴S and ³⁶S which are found in nature and ³⁵S which is man-made and radioactive. Certain sulphurous compounds such as ammonium sulphate and magnesium sulphate are used as fertilisers. Furthermore, creams used to treat skin diseases also contain a small percentage of sulphur in it due to it's effectiveness against skin diseases such as acne. Lastly, sulphur is once of the most important ingredient in the making of gunpowder as without sulphur, the gunpowder will not be that strong. However, these are only a few more significant uses of sulphur. Sulphur is also important in the chemical industry and is also extremely essential for the normal functioning of our body.
• Hydrogen: Hydrogen is a colourless and odourless gas (in room temperature) which belongs to group I of the periodic table, has an atomic number of 1 and a nucleon number of 1 (Most common isotope). It has a melting/freezing point of - 259.2 °C and boiling point of - 252.8 °C and usually comes in the form of water. One of it's unique property is that it is not very reactive in low temperature unless it is activated somehow such as by catalysts but becomes highly reactive just like the other group I elements in environments with high temperature such as the sun. Hydrogen has 3 natural isotopes, the first 2 being stable and the last one radioactive. They are protium which has no neutrons and is the most common of the 3 isotopes, deuterium which has 1 neutron which hardly existed in nature and tritium which has 2 neutrons that also hardly existed in nature and is usually found in nuclear reactors Both deuterium and tritium were once experimented on to produce hydrogen bombs. Liquid hydrogen is used as fuel for rockets due to its high caloric value which means that it releases high amount of energy during combustion which is also why hydrogen is used as the combustion medium in welding torches used to melt metals. Hydrogen is also used as fuel for environmentally friendly cars since it only produce water vapour as a waste product. Another use of hydrogen is that deuterium is used as a fuel for nuclear generators. However, these are not only the uses of hydrogen, hydrogen is a crucial ingredient for several industries such as the chemical industry, food industry, paint industry, fertilizer industry ETC..
• Oxygen: Oxygen is a odourless and colourless gas (in room temperature) which belongs to group VI of the periodic table with an atomic number of 8 and a nucleon number of 16 (Most common isotope). It has a melting/freezing point of  -218.4 °C and boiling point of -183.0 °C and usually comes in the form of metal oxides, water or atmospheric oxygen.  There are 3 naturally occurring isotopes that are found in water, oxygen molecules, or any other natural compounds containing oxygen. They are  ¹⁶O which is the most common among the 3 natural isotopes, ¹⁸O which is very rare and ¹⁷O which is the rarest among the 3 natural isotopes. Oxygen is very important in aerobic respiration which is an important process whereby energy is produced in a living thing. Atmospheric oxygen (O² ) must also be present for combustion to take place which will help provide energy to generators, vehicles ETC.. Liquid oxygen is also used as fuel for spaceships together with hydrogen as there is no oxygen in outer space and the hydrogen fuel would therefore not burn without oxygen out of earth. Furthermore, oxygen is also used for welding, melting or cutting metals by raising the temperature of the burning hydrogen to about 3000 to melt the metal and it also helps oxidise the metal so that it could be broken easily by a hammer when cutting a metal after heating a portion of the metal until it turns red hot. Lastly, ozone is found at the ozone layer above our atmosphere and it helps trap or weaken UV rays from the sun which are harmful to humans and other organisms.

Dot and Cross Diagram:

References:
- http://www.fact-index.com/l/li/list_of_stable_isotopes.html
- http://www.georgiagulfsulfur.com/properties.htm
- http://www.fact-index.com/s/su/sulfur.html#Applications
- http://www.lenntech.com/periodic/elements/h.htm
- http://www.sciencedaily.com/releases/2007/09/070913170108.htm
- http://www.gas-plants.com/oxygen-properties.html
- http://www.jtbaker.com/msds/englishhtml/s8234.htm
- http://www.buzzle.com/articles/uses-of-sulfur.html
- http://www.buzzle.com/articles/uses-of-hydrogen.html
- http://www.buzzle.com/articles/oxygen-uses-of-oxygen.html
- http://education.jlab.org/itselemental/ele016.html
- http://www.webelements.com/sulfur/physics.html
- http://www.suite101.com/content/the-harmful-effects-of-acid-rain-a45501
- Horrible Science - Chemical Chaos by Nick Arnold