1. TEK 8.5 Matter and energy. The student knows that matter is composed of atoms and has chemical and physical properties.

2. The student is expected to: A) Describe the structure of atoms, including the masses, electrical charges, and locations, of protons and neutrons in the nucleus and electrons in the electron cloud. B) Identify that protons determine an element’s identity and valence electrons determine its chemical properties including reactivity. C) Interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements.

3. D) Recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts. E) Investigate how evidence of chemical reactions indicate that new substances with different properties are formed. F) Recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass.

4. Vocabulary Atom Element Subatomic particle Neutron Proton Electron Atomic Theory John Dalton JJ Thomson Ernest Rutherford Neils Bohr Erwin Schrodinger Louis de Broglie

5. Atomic Structure Notes

6. Element -substances that are the building blocks of all matter -made up of one kind of atom -Ex. Carbon, Hydrogen, Oxygen

7. Atom -The smallest particle into which an element can be divided and still maintain the properties of the element. -made up of sub-atomic particles

8. Subatomic Particles 3 main structures 1. Protons 2. Neutrons 3. Electrons

9. Protons (+) particles found in the nucleus of an atom. have a positive charge

10. Neutrons Particles found in the nucleus of an atom. Have a neutral charge

11. Electrons (e - ) Particles found in the electron cloud (orbiting the nucleus) Negatively charged

12. AMUs -atomic mass unit aka Dalton -used to describe the mass of subatomic particles -equal to 1.660538921×10 − 27 kg

13. Sizes of Subatomic Particles ProtonsNeutronsElectrons 1 AMU.0005 AMU

14. Modeling Parts of an Atom

15. parts of an atom. Nucleus Electron Cloud Nucleus makes up 99.99% of atomic mass

16. Atomic Theory -a scientific theory of the nature of matter, which states that matter is composed of discrete units called atoms.

17. Democritus -influential pre-Socratic philosopher -formulated an atomic theory -400 B.C.

18. John Dalton Solid Ball +1803

19. JJ Thomson Plum pudding 1897 Plum Pudding Model Aka Muffin Model Aka Arroz con Leche Model Discovered Electrons

20. Ernest Rutherford Planetary Model 1909 Discovered Protons

21. Neils Bohr Proton Neutron Electron Nucleus 1913

22. Louis de Broglie & Erwin Schrodinger Electron Cloud Model1926

23. 1927 Solvay Conference

24. PERIODIC TABLE Atoms Part II

25. Vocabulary Atomic Number Atomic Mass Atomic Symbol Valence electron Orbital Electron Shell Energy Level Valence shell

26. Atomic Number -reflects the # of protons in the nucleus and electrons in the electron cloud of a balanced atom of that element. ATOMIC NUMBER = # OF PROTONS & ELECTRONS

27. Atomic Number

28. Atomic Mass -the sum of the protons and the average number of neutrons

29. Atomic Mass

30. # of Neutrons Np+p+ - AM= Atomic Mass (rounded to nearest whole number) minus # of protons

31. AM-P=N Example

32. Atomic Symbol

33. Putting it all together Atomic Number Element Symbol Atomic Mass

34. Electron Orbitals aka Electron Shells aka Energy Levels -the amount of energy carried by an electron in an atom -determines the electron’s average distance from the nucleus

35. Energy Levels Nucleus 2 e - 8 e -

36. Nucleus

37. Valence Shell -the outermost shell of an atom in its uncombined state -all atoms want their valence shells filled.

38. Valence Electron electrons located in the valence shell # of valence e- will determine the reactivity of the atom. The more Valence e’s the more stable and HAPPY (Nole Gases) The less valence e’s the more reactive and EXPLOSIVE or UNHAPPY (Alkali Earth Metals)