Particle nature of matter

The miderstanding of molecular motions is necessarily based on quaiitum mechanics, the theory of microscopic physical behaviour worked out in the first quarter of the 20th century. This is because molecules are microscopic systems in which it is impossible—or at least very dangerous —to ignore the dual wave-particle nature of matter first recognized in quaiitum theory by Einstein (in the case of classical waves) and de Broglie (in the case of classical particles). 

Gabel, D., Samuel, K. V., Hunn, D. (1987). Understanding the particle nature of matter. Journal of Chemical Education, 64(S), 695-697. 

De Broglies insight into the wave-particle nature of matter had a profound effect on scientists picture of the atom. The solution to the wave equation led to a new way of looking at the atom. The old certainties of a solid electron circling a nucleus were gone. No longer could one say the electron is here or there. An electron in an atom could be anywhere, although some locations are more likely than others. 

Gabel D.L. (1993). Use of the particle nature of matter in developing conceptual understanding. Journal of Chemical Education 70(3). 193-194. 

Dalton s atomic theory gave chemists a model of the particle nature of matter. However, it also raised new questions. If all elements are made up of atoms, why are there so many different elements What makes one atom different from another atom Experiments in the late 19th century began to suggest that atoms are made up of even smaller particles. Present-day chemistry explains the properties and behavior of substances in terms of three of these smaller particles. You will learn more about each of these particles in Section 2.2. 

In this chapter, you learned to solve several kinds of stoichiometric problems. For each kind, you used the mole concept because when substances react, their particles interact. The number of particles at this sub-microscopic level controls what happens macroscopicaUy. In the next chapter, you will use the mole concept and the particle nature of matter to study the mixtures of substances called solutions. 

Brook, A., Briggs, H., Driver, R. Aspects of Secondary Students Understanding of the Particle Nature of Matter. Leeds 1984 (University of Leeds)... 

Haidar, A.H., Abraham, M.R. A comparison of applied and theoretical knowledge of concepts based on the particle nature of matter. Journal of Research in Science Teaching 29(1991), 611... 

Most people look at a gold nugget and see a shiny metallic substance that can be melted down and made into jewelry. A chemist looks at a substance such as gold and visualizes the internal structure responsible for those external characteristics. Now that we have discussed some of the general features of atoms and elements, we can return to the model of solid, liquid, and gas structures presented in Section 2.1 and continue in our quest to visualize the particle nature of matter. 

Describe solids, liquids, and gases in terms of the particle nature of matter, the degree of motion of the particles, and the degree of attraction between the particles. 

At the end of the 19" century, all everyday and laboratory experience seemed to confirm these classical distinctions between the wave nature of energy and the particle nature of matter. 

The wave nature and particle nature of matter are complementary— the more we know of one, the less we know of the other. 

CARD www.cardunp.ac.za. This site gives information about students conceptual and reasoning difficulties (CARD). It contains many references about a range of topics in chemistry education such as the particle nature of matter, chemical bonding, acids and bases, chemical equilibrium, electrochemistry, stoichiometry, and thermodynamics. 

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