The older a sample of a radioactive material the less radioactive it is the decrease in radioactivity follows a characteristic pattern shown in the graph or decay curve the y axis can represent the radioisotope left or the measured radioactivity.
Revision notes history of atomic structure models isotopes definition explained working out numbers of electrons protons neutrons revising for a level aqa gcse chemistry a level edexcel gcse chemistry ocr gcse 21st century science a level ocr gcse gateway science gcse 91 chemistry exams.
Try this question a speck of uranium dust contains 10 14 atoms it has a mass of 395 x 108 g the half life of uranium 238 is 45 x 10 9 years it is inhaled and lodges in the lung what is the initial rate of disintegration of the dust spec.
This page contains the gcse aqa chemistry atomic structure questions and their answers for revision and understanding atomic structure.
Physics revision site winner of the iop web awards 2010 cyberphysics a physics revision aide for students at ks3 sats ks4 gcse and ks5 a and as level help with gcse physics aqa syllabus a as level and a2 level physics it is written and maintained by a fully qualified british physics teacher topics include atomic and nuclear physics electricity and magnetism heat transfer.
research highlights of nature research journals oct 4 plant science warmer springs may not lead to greener grass nature oct 4 medical research latent hiv infection targeted in monkeys nature oct 3.
As a followup to tuesdays post about the majorityminority public schools in oslo the following brief account reports the latest statistics on the cultural enrichment of schools in austria vienna is the most fully enriched location and seems to be in roughly the same situation as oslo many thanks to hermes for the translation from unzensuriertat.
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1277974 kwjwxajbwjnqta 投稿者archie 投稿日20081013mon 0838 lthomegt more or less not much going on worth mentioning pretty much nothing seems worth.