Ideas about Atoms

1
Ideas about Atoms

• By
• HILAL YILDIZ

2
DEMOCRITUS(b.c.460-370)
3
Democritus

• According to Democritus theory
• All matter consist of invisible particles,
• Atoms are unchangeable,
• A empty space exists between atoms,
• Atoms are solid,
• Atoms are homogeneous,
• Atoms differ in size,shape,mass,postion,arrang
  ement.

4
JOHN DALTON(1766-1844)
5
John Dalton

• John Dalton said that,
• Oxygen is made from only oxygen atom,
  hydrogen from only hydrogen atom and so on. The
  atoms of one element are different from any
  other. Atoms never from one element to another.
• Elements are characterized by atomic mass.
• Different compounds may be formed the same
  elements in different ,but fixed, ratios.

6
J.J.THOMPSON (1856-1940)
7
J. J. Thompson

• He found Cathode ray tubes Plum Pudding atomic
  model.
• In this model,atom is composed of electrons
  surrounded by positive charge to balance the
  electrons negative charge.

8
Brownian Motion Theory

• Brownian Motion is random movement of particles
  suspended in a liquid or mathematical model used
  to describe such random movements.
• For example, test particle has a velocity V and
  fluid particle velocity is v after collision the
  test particle velocity increased.

9
ERNEST RUTHERFORD(1871-1937)
10
Ernest Rutherford

• According to Ernest Rutherford theory,
• Atoms look like square,
• It has proton and electron inside in it, but
  he could not be sure about their position.

11
Alpha-particle scattering

• If the particle a which is inside atom collide an
  electron, it can move by taking out electron
  particles. Also there shouldnt be returning
  because of opposite caherge. Also he thought that
  mass of atom number is equal about mass of atom.

12
JAMES CHADWICK(1891-1974)
13
James Chadwick

• James Chadwick worked with Rutherford about
  neutral particles, but they couldnt achieve
  their goal. Then he continues his experiment,
  and he took out neutral paticles from Be. Thus he
  found neutron.

14
Quarks

• Quark is an elemantary particle and a fundamental
  constituent of matter. Hadrons made off quark.
  The most stable ones are protons and neutrans.
  Quarks are never be lonely, they are all hadrons
  in nature.

15
Extra Task

• Democritus (440 BC) suggested the idea of atoms
  but with no proof. Eventually Robert Boyles
  experiments (1662) supported the idea and in 1738
  Daniel Bernoulli proposed the kinetic theory.
• John Dalton used atomic weights (1805) to support
  the idea, and in 1831 Thomas Graham investigated
  diffusion.
• Henri Becquerel discovered radioactivity (1896)
  and Marie Curie discovered radium (1898). Ernest
  Rutherford discovered alpha and beta rays.
  Rutherford came up with the idea of an atomic
  nucleus.
• Niels Bohr (1913) suggested the idea of electrons
  in orbits with different energies.

16
BIBLIOGRAPHY

• http//en.wikipedia.org/wiki/Plum_pudding_model
• http//en.wikipedia.org/wiki/Brownian_motion
• http//tr.wikipedia.org/wiki/Rutherford_Atom_Model
  i
• http//www.main-board.net/bilim-adamlari/303319
  james-chadwick.html
• http//www.docstoc.com/docs/4581033/democritus-ato
  mic-theory
• http//www.furryelephant.com/content/radioactivity
  /democritus-lavoisier-dalton/