scroll to top
Stuck on your essay?
Get ideas from this essay and see how your work stacks up
Word Count: 427
ATOM PRIOR TO 1900 In the 5th cent BC the Greek philosophers Democritus and Leucippus proposed that matter was made up of tiny indivisible particles they called atom or in Greek a-tomos The reason why they assumed this is because nothing can come from nothing Democritus believed that all atoms were firm and solid but they could not all be the same If all atoms were identical there would be no satisfactory explanation of how they could combine to form everything in different shapes Democritus concluded atom with these ideal qualities invisible because of their extremely small size indivisible as their name indicates solid no void inside eternal because they are perfect surrounded by an empty space to explain their movement and changes in density having an infinite number of shapes to explain the diversity observed in nature Around 1803 John Dalton 1766-1844 developed the first useful atomic theory of matter In the course of his studies on meteorology Dalton concluded that evaporated water exists in air as an independent gas Solid bodies cant occupy the same space at the same time but obviously water and air could Dalton reasoned that if the water and air were composed of discrete particles evaporation might be viewed as a mixing of water particles with air particles He performed a series of experiments on mixtures of gases to determine what effect properties of the individual gases had on the properties of the mixture as a whole While trying to explain the results of those experiments Dalton developed the hypothesis that the sizes of the particles making up different gases must be different In 1808 Daltons A New System of Chemical Philosophy was published In this book he listed the atomic weights of a number of known elements relative to the weight of hydrogen His weights were not entirely accurate but they form the basis for
@Kibin is a lifesaver for my essay right now!!
- Sandra Slivka, student @ UC Berkeley
Wow, this is the best essay help I've ever received!
- Camvu Pham, student @ U of M
If I'd known about @Kibin in college, I would have gotten much more sleep
- Jen Soust, alumni @ UCLA