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A NEW AGE DAWNS Chapter 9 THE MIGHTY ATOM. Presented by: Nihal Lashin Omar Sarwat Mohamed Sadek. General Knowledge about atoms . “All things are made of atoms” the great Caltech physicist Richard Feynman.
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A NEW AGE DAWNS Chapter 9THE MIGHTY ATOM Presented by: Nihal Lashin Omar Sarwat Mohamed Sadek
General Knowledge about atoms • “All things are made of atoms” the great Caltech physicist Richard Feynman. • The basic working arrangements of atoms is the molecule. • What is a molecule?
Chemists way of thinking: Molecules Vs Elements • Properties of an atom: • Tiny • Durable Long lived (10ˆ35 ) • Everywhere • Numerous • Recycled • Indestructible
The size of an atom: • If you want to see a paramecium- a single celled, fresh water creature which is about 0.002 mm, you have to enlarge it 12 meters across BUT • If you want to see an atom in a drop of water you have to enlarge the drop 24 kilometers across ***Can you see how small it is??? • The scale of an atom: One ten-millionth of a millimeter.
History of atoms: • First the idea of atoms developed by the ancient Greeks. • Dalton’s contribution: • Relative size of an atom • Characters of atoms • How atoms fit together
The Viennese physicist Ernest Mach doubted the existence of atoms… “Atoms cannot be perceived by the senses… they are things of thought” he wrote. • The first real hero of the atomic age is Ernest Rutherford.
He received a Nobel Prize for investigations into disintegration of the element. • In Manchester University, he did his most important work in determining the structure and the nature of the atom. • In 1910 he invented the radiation detector. • An atom according to Rutherford was an empty space with a very dense nucleus at the centre.
In 1897 J.J. Thomson discovered the electron • In 1911 C. T. R. Wilson produced the first particle detector. • In 1932 James Chadwick discovered the neutron.
The Atom Revealed • In 1910, Rutherford and his assistant Hans Geiger conducted an Experiment which revealed the internal structure of an atom. • Http://www.youtube.com/watch?v=5pZj0u_XMbc • We will add some more points after the video to further illustrate the experiment and its conclusion.
The structure of an atom as we know now: • It’s made of three things: • Protons which have a positive charge • Electros which have a negative charge • Neutrons which have no charge • Protons and neutrons are packed inside of the nucleus, while electrons spin around outside.
** Protons give an atom its identity, while neutrons add to its mass.