Electricity is a general term for a wide range of events resulting from the presence or flow of an electric charge. These events could be things commonly known such as lightning or static electricity, but an other event possible could be electromagnetic fields. People have been aware of the shocks they received from electric fish and eels for a long time. Old Egyptian texts found named these fish as ‘Thunderers of the Nile’ and they were proclaimed as the ‘protectors’ of all fish. Later on, Ancient Greek, Roman and Arabic physicians wrote about these fish. They knew of the numbing effect of the shocks, and they knew the shocks could move with conducting objects. These electric fish were used as medicine to cure gout or headaches. The theory was that the sudden shock would shake away the sickness. Thales of Miletos made a series of observations around the year 600 BC concerning static electricity. He believed the static was because the objects he rubbed became magnetized because of friction. After him, electricity was no more than an abstract curiosity for millennia until 1600. In the early 19th century, the work became more precise and extensive experiments and observations were made. In the late 19th century, electricity was discovered and it became a tool in science and modern life instead of a scientific curiosity. People like Nikola Tesla and Thomas Edison showed up and electricity became a necessary force for the Second Industrial Revolution.

Electricity comes from atoms. The protons and neutrons create the center, the nucleus. The protons are positively charged and electrons, which rotate around the nucleus, are negatively charged. The neutrons, hence the name, are neutral. They are not charged. The actual electricity comes from when the electrons move from one atom to the other. Negatively-charged electrons are always attracted to positively-charged protons.

Some atoms are excellent at conducting because there are tracks which the electrons follow. The electrons mostly stick to the closest track to the nucleus because it requires less energy. If the track the most extended to the outside is clear enough of other electrons, the electrons can jump from one track to another and exit their previous atom to enter a new one. These atoms are Conductors. If the track isn’t clear or if the atom holds on tightly to it’s electrons, the electrons cannot move and no electricity is created. Another reason why some atoms conduct better than others is because of their Atomic Number. This number is written on the periodic table of the elements, and it basically tells you how many protons are in the nucleus of one atom from that element. The positively-charged protons attract negatively-charged electrons, making the passing from one atom to the other more tempting and once the electrons are moving, the attraction makes it easier for them to move.

References: http://en.wikipedia.org/wiki/Electricity,http://www.pbs.org/transistor/science/info/conductors.html,http://en.wikipedia.org/wiki/Atomic_number,http://www.pcguide.com/ref/power/ext/basicsWhat-c.html

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An atom is the smallest piece of an element which still has the element’s chemical properties. They are made up of smaller particles called protons, neutrons and electrons. The protons and neutrons bond together in the middle to form the nucleus and the electrons rotate around this nucleus in a cloud. The ratio of protons to neutrons is unique to one sort of atom. An element is lots of atoms, but they all contain the same amount of protons to neutrons. If two sorts of atoms combined, a compound would be created. Some different sorts of atoms are glad to bond together and form molecules (oxygen + chlorine), but others do not bond very well (neon + argon).

A molecule is made up of at least two atoms held together with very strong chemical bonds. These bonds are made because of the constant passing of electrons between atoms. A molecule is the smallest particle, next to atoms, in a chemical compound or element that actually has the chemical properties of that compound or element.

If you find this hard to understand, visualise a pile of paper clips which are all the same. They all have the same colour, size, and weight. If you divide your pile into two separate equal piles, and divide those piles in two, eventually, you will have one paper clip per pile. These can represent an atom. Your paperclip is still useable (i.e. it still has it’s chemical properties), but if you divide even more by cutting the paper clips in half, they won’t be able to actually hold paper. Now visualise a different pile of paper clips, but they are all still the same. Separate them down like the first pile and you get your atoms. Then take a paper clip from each pile and clip them in together. You have now created a molecule, i.e. two atoms joined chemically. The full pile of all the same paper clips (atoms) would represent an element.

References:http://education.jlab.org/qa/element.html,http://science.howstuffworks.com/atom1.ht, http://en.wikipedia.org/wiki/Molecul,http://whatis.techtarget.com/definition/0,,sid9_gci856651,00.html

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