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Everything posted by Primarygun

  1. the single bond enthalpy of oxygen and sulphur are +142 and +264 respectively, why oxygen atom has a much smaller single bond enthalpy than sulphur atom ?may anyone please expalin the large difference?
  2. I wanna include the html command img src for a Christmas Card
  3. How can I use html code in yahoo email? I can't find any button for turning the html code on. I could find that in the signature choice.
  4. In my school, we invited five judges to give a mark to every musicial performers. However, their judging systems are not identical, even there's an unallowable discrepancies among the data. This gives rise to a large standard deviation for one examiner and a small one to some others. Should I reconcile the discrepancies but reducing the standard deviation by means of packing the graph along the x-axis more closely? how do you handle it? I have no idea but I undertake the task for I forsee unfair matter would rise after the announcement.
  5. the old version refers to the environment that the old windows give. the window nt , 98
  6. Consider a man riding a bicycle on a horizontal road around a circle. The situation is as simple as one imagine. If we need to find the angle which the inclined bicycle makes with the horizontal ground, we consider the torque. But why can't we take the point of contact of the bicycle and the ground into account? Error yields showing that there's always a net torque by the weight to rotate the bicycle. Anyone helps? please
  7. ok I found it. Copy the image and then paste it will give it a higher priority to be put on a fronter position/ But does this affect the data processing ?
  8. thanks 5614 I imported an image into the access form. How can I make the other images on top of this newly added image? I want to use it as the background image.
  9. thanks guys. Is that any plug-in that allows the window to be decorated by photoshops?
  10. When I switch on my computer, there jumps out a window saying something about the svhost.exe has error and the process has to be terminated. Then, the system lags for a few seconds and the XP environment then goes out and turns into the old one. Why does this happen? How can I solve it ?
  11. The form created by the microsoft access is not very beautiful though the design is very useful and easy to follow. How do you decorate your form produced with access?
  12. How can I get rid of the human voice in a song? I wanna use it for participation of the singing contest. It is originally in the form of mp3. Thanks for kind attention.
  13. Hello, I'm a firefox user. I'd like to change my default pdf reader from Adobe Reader to Foxit Reader. How can I do this? Foxit reader offers a neater and faster way compared to Adobe reader though the latter offers more functions.
  14. With excess iodide added, one mole of iodate can generate 3 moles of iodine. What's equation of oxidation of thiosulphate by iodate? I can't figure it out. However, I guess that it cannot yield the same effect compared to iodine which can be produced by the iodate.
  15. My teacher suggested me adding potassium iodide into a solution of acidified vitamin C solution and then later add potassium iodate solution into the mixture. Is it a bad to construct an experiment like this? Is it better if we produce iodine in another beaker and then later add it into vitamin C solution?
  16. How does iodate ion react with ascorbic acid? How can I prevent it from occuring when I wanna to use iodine to oxide the acid instead so as to find out the percentage by mass of the acid in a vitamin C tablet.
  17. About the emission line spectrum, what factors affect the formation of the picture? My books said that helium could probably have a similar pattern as hydrogen spectrum but it didn't mention whether the case still applies for lithium and hydrogen. Moreover, it is not only the principal quantum shell which determines the wavelength of the radiation released, right?
  18. Oh the point is the centre of mass. Thank you
  19. I don't know how to find the point on an object where the axis of rotation passes through it. ------------------------------------ Imagine, the above is a thick strip. With only mass 10M on the left and 1M on the right. When it is left falling freely in air, what do you recommend about the rotation of it? I don't know if it rotates around a fixed axis of rotation.
  20. I don't know but it is not ABC. I pursue it first.
  21. Hello Here I want to ask a few questions and I hope some of you will be kind enough to tell me. 1. My book says the evidence of the sub-shell is from the graph of the pattern of the first ionization enthalpy of the elements. How does this work? I'm quite opposed since I don't think it is a fair comparison to show that the difference in I.E. is indeed primarily due to the sub-shell. 2. We can find that ionization enthalpy of the sodium atoms by finding the difference between the energy level n=infinity and n=3, right? 3. I glazed at many books very quick in the library and they all only give the first five series of the spectral lines of hydrogen atom, there exists other series, right? Thanks for kind attention
  22. I heard of an essay written by a Nobel winner in the economy field. The title is "Hong Kong Wrong" It is published in the US newspaper but it is indeed too far for me to reach it. May anyone give me the link to the essay?
  23. I always want to improve my writing and I'm still inept at writing a good essay. I want to change the type of sentence, probably by the structure in a more humorous way. Is there any forum comprising a lot of helpers willing to rewrite a sentence or a paragraph for me if there's a request? Thank you
  24. Thanks. You give me an excellent resort to question 3 and 4. However, I am still confused with the second question (2).
  25. Hello, 1.May anyone explain why at higher temperature, the excited electrons can settle at a higher energy level? 2.What does the radial probability mean? Meaning the probability of finding an electron at a specific distance from the nucleus or an electron of a particular orbital. 3. Why does Lithium ion have more energy level than hydrogen atom ? And isn't it that hydrogen atom have all the energy levels from n=1 to n=infinity? 4.Orbitals of a particular sub-shell do not possess identical energy only when they are under magnetic field, right? And generally, the orbitals of the same sub-shell have the same properties, doesn't them? Thank you for your kind attention.
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