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  • Location
    Hong Kong Special Administrative region
  • Interests
    Football, thinking, laughing
  • College Major/Degree
    On summer holiday
  • Favorite Area of Science
    Maths, Chemistry, physics, biology
  • Biography
    A good person compared to bad people.A bad people compared to a good person.
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  • Organism

Primarygun's Achievements


Organism (8/13)



  1. Hello! We have created a science forum. Researchers, professors, post graduate students and undergraduate students are invited to join/register our forum.


    This is the link to my forum. It is still under construction and will be fully active from 1is august. Last date of registration is 15th august, so please join it as soon as possible. It will be a great pleasure for me, if you join it.


    Nikhil aggarwal

    University of Delhi, India

  2. Very often, I noticed that there's a file type nfo in CD. What's the use of the nfo file?? It occupies only a very subtle space.
  3. I tried Norton 360 and Norton internet security 2006 Norton 360 eats up much less resources for running. However, it does not allow to scan files by locations.
  4. All stars rise from the east except at the poles. However, it is hard to determine whether the moon comes from the south-east or the north-east even when the relative positions of the earth and the moon is given. Is there anybody who has a clever method to determine the direction in which the moon rises?
  5. acknowledge for the explanation. 400 million years ago, we have only 22 hours in one sidereal day.
  6. The moon's orbital around the earth is getting larger and larger. Why does this happen?
  7. 1. Where is the sun in its ecliptic when it is the hottest period in the northen hemisphere? 2. Take a look at the picture I upoloaded. Why is the time that the sun is at the meridian again 12:30 rather at at noon? How do you explain the wave shape of the curve? I'd think that it's because the discrepancies between the sidereal day and the apparent solar day, I don't know if it is the answer
  8. What's the difference between a battery and capacity that makes the only the former can be the e.m.f. in a normal electric circuit?
  9. Isn't the reaction between sugar and chlorate a kind of simple redox reaction involving an acidic medium? Is a suplhur-containing substance a must for the reaction to occur?
  10. Recently, I saw two types of file in the internet. One is HDTV and the other is DVDRip. What is the difference between them? What about the size, the operators, the quality, the sound? Thanks
  11. Is the rate constant in the rate equation equivalent to that in the arrhenius equation? Does the arrhenius equation describe the overall rate of reaction or can be interpreted to compute the rate of forward reaction and backward reaction respectively? If it could be employed to deal with both sides separately, then I know why the decay of radioactive substance has a constant half-life, otherwise, it still seems to be an enigma to me though after exhausting search in the web. Please help
  12. Here are a few questions puzzling me for a long period of time. 1. If reactant X is converted to product Z through a intermediate Y. Then, it is unfair to compare the rate constant of (y to z and x to y) just on the basis of the activation energy for the steps, right? arrhenius equation : k=A *exp(Ea/RT) What does A mean and under what circumstances does it change. 2. Recently, my class took a laboratory experiment but I am not sure about the validity of theorem behind. In the experiment, four different set-ups with the concentration of the propanone solution as the sole variable factor are used. At fixed time interval, the concentration of the remaining iodine concentration was recorded. The problem is here, We plot the rate of reaction against the concentration of the propanone which are set in different values in four set-ups. but the rate of reaction is taken as the slope of the graph of the concentration of iodine solution VS the time. Aren't the slopes only the average rate of the reaction, I bet initial rate should be taken, right?
  13. What is the resistance of a capacitor? From the data of experiement, I was convinced that the resistance tends to zero. Is this the truth? There's a part of empty space between two parallel plates. Isn't the resistance very large as it seems it's hard for electrons to pass through these spaces. How do you reconcile the two facts?
  14. I am not sure what the point of inflection of the titration curve means. IN the case of only acid and base titration, say NaOH and HCl, I could perceive the term in the way that the point is when the dominating ion changes.( from OH- to H+)
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