Structureofatomppt 140819083924-phpapp01
- 2. PREPARED BY LEKSHMI.S.G PHYSICAL SCIENCE REG NO: 13357003 BNVCTE,THIRUVALLAM
- 4. ļAll matter is made up of atoms. ļAtoms of an element are identical. ļEach element has different atoms. ļAtoms can engage in a chemical reactions. ļAtoms can neither be created nor be destroyed. ļAtoms are indivisible. Atomic Theory John Dalton (1776-1884)
- 5. ļ¼atom has a positively charged central part (nucleus) ļ¼Electrons are distributed around nucleus ļ¼Mass of an atom is concentrated at nucleus. ļ¼Compared with total volume of an atom, the volume of nucleus is meager Rutherfordās Atomic Model Ernest Rutherford (1871-1937)
- 6. Solar system Rutherfordās atom model Planetary model of atom
- 7. Bohr's Model of the Atom Niels Bohr 1913
- 8. Bohr's Model of the Atom ļ§ electrons orbit the nucleus like planets orbit the sun
- 9. Bohr's Model of the Atom ļ§ electrons fills the orbits closest to the nucleus e.g. fluorine: #P = 9 #e- = 9 #N = 10 9P 10N
- 10. ļ§ each orbit can hold a specific maximum number of electrons Shell maximum no: of electrons 1 - K 2 - L 3 - M 4 - N Bohr's Model of the Atom 2 8 18 32
- 12. What is the structure of an atom? ā¢ Nucleus - center of the atom ļ¶Home of Protons and Neutrons ļ¶Has a positive charge ā¢ Proton ļ¶Has a relative mass of 1 ļ¶Has a positive (+) charge ļ¶Determines the atomic number ļ¶Found inside the nucleus
- 13. What is the structure of an atom? ā¢ Neutron ļ¶Has no (0) charge ļ¶Has a relative mass of 1 ļ¶Found inside the nucleus
- 14. What is the structure of an atom? ā¢ Electron ļ¶Has a negative (-) charge ļ¶Found outside the nucleus ā¢ Rutherford atom model - electrons are around the nucleus ā¢ Bohr model ā electrons are in specific energy levels called shells
- 15. How are p, n, e related? ā¢ No: protons = No: electrons ā¢ No: protons = atomic number ā¢ No: protons + No:neutrons = mass number ā¢ No: neutrons=mass no: - atomic no:
- 16. ATOMIC STRUCTUREATOMIC STRUCTURE the number of protons in an atom the number of protons and neutrons in an atom HeHe 22 44Atomic mass Atomic number number of electrons = number of protons