A Harmful Compound by Ryan Ong

The harmful compound that I have identified is Sulfur dioxide.

Harmless constituent elements: Oxygen(O) and Sulfur(S)

How is Sulfur dioxide formed?

Sulfur dioxide is the product of the burning of sulfur:

S8 + 8 O2 → 8 SO2

Sulfur dioxide is a noticeable component in the atmosphere, especially following volcanic eruptions.According to the United States Environmental Protection Agency (EPA), the following amount of sulfur dioxide was released in the U.S. per year.

How harmful is Sulfur dioxide?

Sulfur dioxide is a major air pollutant and has significant impacts upon human health. In addition the concentration of sulfur dioxide in the atmosphere can influence the habitat suitability for plant communities as well as animal life.[10] Sulfur dioxide emissions are a precursor to acid rain and atmospheric particulates. Due largely to the US EPA’s Acid Rain Program, the U.S. has witnessed a 33 percent decrease in emissions between 1983 and 2002. This improvement resulted in part from flue gas desulfurization, a technology that enables SO2to be chemically bound in power plants burning sulfur-containing coal or oil. In particular,calcium oxide (lime) reacts with sulfur dioxide to form calcium sulfite:

CaO + SO2 → CaSO3

Aerobic oxidation of the CaSO3 gives CaSO4, anhydrite. Most gypsum sold in Europe comes from flue gas desulfurization.

This is my dot and cross diagram:

Sources: http://en.wikipedia.org/wiki/Sulfur_dioxide

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg5kKDSK7UaqdwkNKMtOquHfO-2waGD21ArkpD4PolWA5FE_-FQgp2lXwG3Bb2FDBct508SOC4bYMauzhVDMnGObf93P8hpuEah0BhXQLYWaHf767hB27KgFJNIoFKaXlUSo8RBhGiql93z/s320/Science.jpg

LSS- Online Learning (Benedict Chin)

The harmful Compound which I have researched is : Methane(CH₄ .) Methane is not toxic, but it is extremely flammable and my form explosive mixtures with air. It may also displace oxygen in an enclosed area. It degrades the ozone layer. It is known to everyone in common terms, as fart. 

What type of bonding is Methane under? 

Methane goes through Covalent bonding, which is the sharing of electrons from two non-metals. 

In this case, Methane is bonded by:

: Carbon(C) 

 :Hydrogen(H).

The electrons of one carbon atom shares with the electrons of four other hydrogen atoms, to form methane.

Carbon's electronic configuration is 2.4, where it can give or receive 4 more electrons to its valence shell to obtain full and stable valence shell. Carbon has atomic number :6 and is in Group : IV

Carbon are highly stable, and are not likely to react with other elements to cause explosions and stuff.

Hydrogen however has just one electron, so it takes 4 hydrogen to give to the carbon atom, to obtain a full shell. hence the formula,  CH_4.     

Hydrogen is very harmless, as it occupies most of the air which we breathe in daily life; because of its abundance, it is harmless. It has atomic number 1, and is in Group : I 

Below is how it is illustrated when 4 hydrogen atoms share with one carbon atom to form a methane compound- flammable- CH₄

Bibliography:

http://www.google.com.sg/images?hl=en&xhr=t&q=dot+and+cross+diagram+for+methane&cp=28&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=1599&bih=789

http://en.wikipedia.org/wiki/Methane

http://en.wikipedia.org/wiki/Carbon

http://en.wikipedia.org/wiki/Hydrogen

Science Online Learning: Harmful compounds with harmless elements

1.0 Intro

What I am doing on is benzene (C6H6). Benzene is a colorless and highly flammable liquid with a sweet smell. It can be found in cigrattes and cigars. Michael Faraday discovered this chemical in 1825 from the oily residue derived from the production of illuminating gas.

1.1 Uses of benzene after being discovered

In the 19th and early-20th centuries, benzene was used as an after-shave lotion because of its pleasant smell. Prior to the 1920s, benzene was frequently used as an industrial solvent, especially for degreasing metal.

1.2 Uses of benzene today

Today, benzene is used mainly as an intermediate to make other chemicals. Its most widely-produced derivatives include styrene, which is used to make polymers and plastics. Smaller amounts of benzene are used to make some types of rubbers, lubricants, dyes, detergents, drugs, explosives, napalm, and pesticides.

1.3 Formation

It is formed by two harmless elements: Carbon and Hydrogen.

1.31 Carbon

Carbon has an atomic number of 6, and a mass number of 12. It is a harmless, non metallic element and is the fourth most abundant element in the universe (hydrogen, helium, and oxygen are found in higher amounts, by mass).

1.32 Hydrogen

Hydrogen has the atomic number of 1, a mass number of 1, and is the first element of the periodic table. It takes up 75% of the universe. However, it is relatively rare on earth. Hydrogen is extremely flammable, and is always associated with the famous explosion of the Hindenburg airship.

1.4 Harmful aspects of benzene

1.41 Overview

Benzene exposure has serious health effects. The American Petroleum Institute stated in 1948 that "it is generally considered that the only absolutely safe concentration for benzene is zero." The US Department of Health and Human Services classifies benzene as a human carcinogen.

1.42 Short term effects

The short-term breathing of high levels of benzene can result in death; low levels can cause drowsiness, dizziness, rapid heart rate, headaches, tremors, confusion, and unconsciousness. Eating or drinking foods containing high levels of benzene can cause vomiting, irritation of the stomach, dizziness, sleepiness, convulsions, and death.

1.43 Long Term effects

Long-term exposure to excessive levels of benzene in the air causes leukemia, a potentially fatal cancer of the blood-forming organs, in susceptible individuals.

LSS- online learning (Mark Soh)

This is carbon monoxide. It is made up of 2 harmless elements, one atom of carbon and one atom of oxide. This results in carbon monoxide.
Carbon monoxide is a colourless, odorless and tastless gas that is slightly lighter than air. It is toxic to humans and animals in large amounts.
This compound in bonded through covalent bonding as both carbon and oxide are non-metals.

Carbon: 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.
Oxide:An oxide is an anion of oxygen in the oxidation state of -2 or a chemical compound formally containing an oxygen in this state. Most of the Earth's crust consists of oxides. Oxides result when elements are oxidized by oxygen in air.
Formation: In carbon, it is four electrons away from becoming a noble gas and oxide is two short from becoming a noble gas. Hence a coordinate covalent bond is formed and carbon monoxide is formed.

Dot and cross: Above

References: www.wikipedia.com
www.wisegeek.com

Online Lesson

Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula NH3. Both nitrogen and hydrogen are harmless gases that we breathe in everyday but ammonia is both caustic and hazardous. It is also a colourless gas with a pungent odour. It is produced by the decaying process of plants and animals, it is also found in small quantities in rainwater. It is lighter than air, its density being 0.589 times that of air. It is easily liquefied due to the strong hydrogen bonding between molecules; the liquid boils at −33.3 °C, and solidifies at −77.7 °C to white crystals. Ammonia does not burn readily or sustain combustion.

The type of chemical bonding involved is covalent bonds as nitrogen and hydrogen are non-metals, so the there are 3 hydrogen atoms to share their only electron with 1 nitrogen atom to become stable. Ammonia is manufactured by the reaction of hydrogen with nitrogen in the presence of an iron catalyst, which is known as the Haber-Bosch process.

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.It is a colourless, odourless and tasteless gas that takes up 78% of the volume of the Earth’s atmosphere and 75% by weight in Earth’s atmosphere. Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H, with an average atomic weight of 1. It is the lightest and the most abundant element in the universe.
Dot and cross diagram (See above)

Done by: Dong Dexin(11) 2A2


Reference:
http://en.labs.wikimedia.org/wiki/A-level_Chemistry/OCR_(Salters)/Molecular_geometry
http://en.wikipedia.org/wiki/Ammonia
http://en.wikipedia.org/wiki/Nitrogen
http://en.wikipedia.org/wiki/Hydrogen