1.3- THE ARRANGEMENT OF THE ELECTRONS Flashcards
What did Niels Bohr put forward in 1913?
idea that the atom consisted of a tiny positive nucleus orbited by negatively charged electrons to form an atom like a tiny solar system
How did the electrons orbit?
electrons orbited in shells of fixed size
What did the movement of electrons from one shell to the next explain?
how atoms absorbed and gave out light
What was this recognized as the beginning of?
movement of electrons from one shell to next- atom absorbs/ gives out light
quantum theory
What did Erwin Schrödinger work out in 1926?
an equation that used the idea that electrons had some of the properties of waves as well as those of particles
What did Erwin Schrödinger’s equation lead to?
a theory called quantum mechanics which can be used to predict the behavior of sub-atomic particles
What did James Chadwick discover in 1932?
neutrons
What ideas did Gilbert Lewis put forward? (3)
inertness of the noble gases was related to their having full outer shells of electrons
ions were formed by atoms losing or gaining electrons to attain full outer shells
atoms could bond by sharing electrons to form full outer shells
What are Lewis’ theories the basis of?
modern ideas of chemical bonding and explain the formulae of many simple compound using the idea that atoms tend to gain the stable electronic structure of the nearest noble gas
What do early theories model the electron as?
a minute solid particle
What do later theories suggest you can also think of electrons as?
smeared out clouds of charge, so you can never say exactly where an electron is at any moment
What is the probability that an electron can be found in a particular volume of space that has a particular shape?
merely state the probability
How is Dalton’s model of the atom used?
explain the geometries of crystals
How is Bohr’s model of the atom used?
simple model of ionic and covalent bonding
How is the charge cloud idea used?
for a more sophisticated explanation of bonding and the shapes of molecules
