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Tuesday, March 17, 2009

Group 1 elements (Li, Na, K, Rb, Cs) - ChlorineOxygenWater




































Lithium is a Group 1 element containing just a single valence electron. 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.



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).


Potassium is a metal and is the seventh most abundant and makes up about 1.5 % by weight of the earth's crust. Potassium is an essential constituent for plant growth and it is found in most soils. It is also a vital element in the human diet.
Potassium is never found free in nature, but is obtained by electrolysis of the chloride or hydroxide, much in the same manner as prepared by Davy. It is one of the most reactive and electropositive of metals and, apart from lithium, it is the least dense known metal. It is soft and easily cut with a knife. It is silvery in appearance immediately after a fresh surface is exposed. It oxidises very rapidly in air and must be stored under argon or under a suitable mineral oil. As do all the other metals of the alkali group, it decomposes in water with the evolution of hydrogen. It usually catches fire during the reaction with water. Potassium and its salts impart a lilac colour to flames.



19 comments:

  1. group 1?group 17?
    傻傻分不清楚
    (sha sha fen bu qing chu )
    haha if still x understand
    ask the chiense
    dun ask me
    hahaha

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  2. Aloha....I am aurelia tay boon kiat.I love you all. Muah......................

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  3. This comment has been removed by the author.

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  4. guys, can u look closely at the potassium... the one v tried in lab was actually hydrated potassium(potassium after removing its water content)... its suppose to look like in the picture....

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  5. you guys shouldn't be talking shit here..i mean..look at the topic...someone's mad right now..didn't realize that didn't you?

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  6. what's the differences between hydrated and non-hydrated potassium?I mean its still the same..the one we've tried in the lab was in a jar with oil right?..hydrated..u meant by the oil?

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  7. To:act cute ppl
    x geli plzzz
    kiss x kaitan with chemistry

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  8. yaa.. kaitan with biology only..
    wkakaka!

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  9. aurelia tay boon kiat????
    aurelia + albert???
    yiak
    hard to imagine

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  10. hahahahah......
    ~y hard owh natalie,,,????

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  11. eh, kamu mahu kena cikgu marah ka ? discuss chemistry , not discuss abt kiss or what ..

    thank you

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  12. ala cclya,
    u can imagine meh?
    jellyfish + mr.bean
    n
    kenneth,this is chemistry bah
    c
    "jellyfish + mr bean ->???"
    it x chemistry equantion meh?

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  13. ?????????????????????????????????????????

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  14. hmmm, my dearest playful students.. get focused....! Jessel n Kenneth r right... I'm not interested with ur kissing thoeries...
    Bout the POtassium jessel, in the lab in the paraffin oil was sodium... potassium was that white powder like salt one.. hydrates meand removed water...

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