ATOMIC MODELS.ppt
- 2. Atomic Models Dalton’s Model of Atom Thomson’s Model of Atom Rutherford’s Model of Atom n = 1 n = 2 n = 3 Bohr’s Model of Atom
- 3. A. DALTON’S MODEL OF ATOM John Dalton Dalton’s Model of Atom
- 4. DALTON’S MODEL OF ATOM In 1808, John Dalton proposed theory of matter. Atom is exceedingly small indestructible particles
- 5. DALTON’S THEORY Atoms cannot be broken up by any chemical process Atom of the same element are identical, but different from atoms of any other element Atom of different elements have different masses That compounds are formed by atoms of different element joining together in simple ratio That the masses of elements which combine together can be used to find the relative masses of atoms
- 6. B. THOMSON’S MODEL OF ATOM J.J Thomson The plum pudding model of atom Electron Spherical cloud of positive charge
- 7. Thomson’s Postulate Thomson postulated that an atom consisted of a diffuse sphere cloud of positive charge with negative electrons embedded randomly in it This model is often called the plum pudding model
- 8. C. RUTHERFORD’S MODEL OF ATOM Ernest Rutherford
- 9. The Rutherford’s Experiment Almost all of alpha particles passed through the foil undeflected Some alpha particles experienced slight deflection Only very small number of alpha particles suffered rather serious deflections as passed through the foil A much smaller umber of alpha particles were bounced back toward the particle source
- 10. Rutherford’s Model of Atom • The atom consisted of a heavy, small nucleus surrounded by electrons
- 11. D. BOHR’S MODEL OF ATOM Niels Bohr Bohr’s Model of Atom
- 12. Bohr’s Model of Hydrogen Atom • The electron in the hydrogen atom travels around the nucleus in a circular orbit. • The energy of the electron in an orbit is proportional to the distance from the nucleus • Only a limited number of orbit with certain energies are allowed. Each orbit corresponds to energy level of the electron and is identified by a quantum number. • Light is absorbed when an electron jumps to a higher energy orbit and emitted when electron falls into a lower energy orbit • The energy of the light emitted or absorbed is equal to the difference between energy of the orbit
- 13. E. MODERN MODEL OF ATOM Erwin Schodinger De Broglie Werner Heisenberg Modern model of atom
- 14. Modern Model of Atom • Atoms are made of protons, neutrons, and electrons. The protons and neutrons are found in the nucleus of the atom while electrons surround the nucleus. • A “cloud” of electron rapidly moving, negatively charged electron occupies virtually all the atomic volume and surround the tiny , central nucleus • A nucleus contain virtually all the mass of the atom.
- 15. Modern Model of Atom • Electron are arranged around the nucleus of an atom, in shells. The shells are numbered 1, 2, 3, etc, starting from the nucleus. These numbers are known as quantum numbers. • Each shell consists of a number of subshells, labelled s, p,d, or f. • Each subshell contain a number of orbitals, in which the electrons are placed. The number of orbitals in each subshell depend on the type of subshell • Each orbital can be represented by a square box. Maximum electron in each orbital is two electrons.
- 16. GOOD LUCK AND SEE YOU Drs. Upik sutrisno, NIP: 131 660 675/196001 1987 02 1 003 SMA NEGERI I KEDIRI JAWA TIMUR