You should all know that you have to study past papers on your own as well as refer updated material on the scope of your study to achieve high grades in such a competitive exam like G.C.E. A/L. In this quest of exam excellence, it is needless to say that you have to be sure about the quality of the material you refer. The books, reviews, notes you use, should be of relevant standard of course the authorship should pertain to an accredited professional of the corresponding field.
But at the moment, when it comes to the science stream, it has been more frequent that students as well as teachers worry about the inadequacy of education material, published in English inclusive of both theoretical aspects and past paper reviews for G.C.E A/L students. Their feedback reflects the hardship they undergo at the absence of a proper publication, especially in English medium. In fact it was this reason that was behind of this publication.
You can be sure that this English publication retains its original blue print plus its unique quality that has been inherited from Sinhalese publication.
It would be really better if there could be some other English publications covering other subjects for the English medium A/L students. This would be an immense contribution for their education.
I am grateful to students of LivePhysics, Roshan David for making the attractive cover page, Chathusha Wijenayake, Lakmin Wikramasinghe and Rumini Rupage for their valuable assistance in the process of publication and in typesetting this book.
Special thanks goes to Mr. Sanjeewa Dharmawardana, teacher of Musaeus college, who encourage me to prepare this book for the benefit of English medium students. Without him this would never have been materialized.
Professor S.R.D. Rosa