The development of the atomic structure

Physical science module 4

1. THE DEVELOPMENT OF THE ATOMIC STRUCTURE MODULE 4

2. For by him were all things created, that are in heaven, and that are in earth, visible and invisible , whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him: And he is before all things, and by him all things consist. Colossians 1:16-17

3. The Discovery of Protons, Electrons and Neutrons Thomson’s Atomic Model

4. Eugen Goldstein (1850-1930) He discovered the positively charged subatomic particle as a component of anode rays (also called rays.) He coined the term proton for the positively charged particle in an atom. Ernest Rutherford (1871-1937)

5. Joseph John Thomson (1856-1940) He discovered that an atom is also composed of negatively charged particles which were named electrons.

6. Most of the alpha particles passed through the gold foil undeflected . Some alpha particles passed through the gold foil with large angles of deflection. A smaller number of alpha particles bounced back in the direction from which they came.

7. The central part of the atom is a dense positively charged portion wherein the proton is located. An atom is mostly an empty space that has a nucleus and electrons revolving around it. Ernest Rutherford (1871-1937) James C hadwick (1891-1974) He discovered the neutral particles , which called neutrons , found in the nucleus of an atom.

8. James Chadwick and Neutron Experiment (1932)

9. (A )mass number = ( protons + neutrons) ( Z )atomic number= ( number of protons ) (e ) atomic charge = ( protons - electrons ) # of neutron= mass number ( A )-atomic number ( Z ) Generally , the number of protons is equivalent to the number of electrons, except in ion formation, where an atom may donate or accept in ion formation, where an atom may donate or accept an electron.

10. Formula Element’s Name Element’s Symbol Mass Number/ Atomic Weight (A) Atomic Number (Z) Number of Protons Number of Electrons Number of Neutrons Iron Fe 56 26 26 26 30 Zinc Zn 65 30 30 30 35 A-Z= # of Neutron 56-26= 30 A-Z= # of Neutron 65-30= 35

11. Arrangement of Elements in the Periodic Table

12. Henry Moseley (1887-1915)

13. Ernest Rutherford Conflict James Maxwell The particles will gradually lose energy by emitting radiation when a body moves in an orbit around an oppositely charged body.

14. Niels Bohr (1885-1962)

15. Max Planck (1858-1957) Quantum Concept Albert Einstein (1879-1955) Quantum Concept

16. Niels Bohr’s postulates An electron can revolve around an atom following its specified orbital. An electron does not emit radiation if it revolves only around its allowed orbital. Moving from one orbital to another, which is called quantum leap , will allow the electron to gain or lose energy.

17. Ground State and Excited State

18. Thank you for listening!

19. Activities for Module 4 Activity 4: What Have I Learned So Far? (Page 26) Activity 2: What Have I Learned So Far? ( Page 23 ) Activity 3:Complete the table by identifying the unknown using the given information . Element’s Name Element’s Symbol Mass Number/ Atomic Weight (A) Atomic Number (Z) Number of Protons Number of Electrons Number of Neutrons Sodium 23 11 Cl 17 18 12 6 Aluminum Activity 1: Complete the table by identifying the unknown using the given information.