1. CHEMISTRY UNIT 2 THE STRUCTURE OF THE ATOM AND THE PERIODIC TABLE

2. STRUCTURE OF THE ATOM STRUCTURE & ARRANGEMENT OF PERIODIC TABLE TRENDS AND PATTERNS ON PERIODIC TABLE

3.  Nucleus  Center of an atom  Made up of:  Protons  Positive charge  Neutrons  Neutral charge  Electron Cloud  Surrounds the nucleus  Made up of:  Electrons  Negative charge THE STRUCTURE OF AN ATOM - TWO PARTS

4. Atom Nucleus Center of atom Proton Positive Charge Neutron Neutral Charge Electron Cloud Surrounds the nucleus Electron Negative Charge

5. Positively charged Atoms of the same element have the same number of protons.  atomic number No two elements have the same atomic number. Change # of protons?  Different element PROTONS

7. CHECK YOUR UNDERSTANDING Element Atomic Number Protons (p + ) 1 Platinum 16 Fluorine 79 Calcium

8. Neutrally charged Atoms of the same element may have different number of neutrons.  Mass Number  Neutrons + Protons Change # of neutrons?  Different isotope NEUTRONS Hydrogen

9. Most naturally occurring isotopes are stable  A few naturally occurring isotopes and all man- made isotopes are unstable Unstable isotopes can become stable by releasing different types of particles.  Radioactive Decay ISOTOPES

10. CHECK YOUR UNDERSTANDING URANIUM Mass Number235 Atomic Number Number of Neutrons 143 URANIUM Mass Number238 Atomic Number Number of Neutrons

11. Negatively charged Atoms of the same element may have different numbers of electrons Atoms neutral unless stated otherwise  Charge Change # of Electrons?  Ion ELECTRONS

12.  Electrons have energy  kinetic Level How Many Electrons Fit in the Level 12 28 318 432 ELECTRON CLOUD

13. CHECK YOUR UNDERSTANDING Atom/Ion Symbol Atomic Number ProtonsChargeElectrons 17 I 1210 19+1 5654 36 8-2 -318

14. ISOTOPE NOTATION

15. How many protons? How many neutrons? How many electrons? CHECK YOUR UNDERSTANDING

16. REVIEW Atom Nucleus Center of atom Proton Positive Charge Change? New atom Neutron Neutral Charge Change? New isotope Electron Cloud Surrounds the nucleus Electron Negative ChargeChange? New ion

17. STRUCTURE & ARRANGEMENT OF THE PERIODIC TABLE STRUCTURE OF THE ATOM STRUCTURE & ARRANGEMENT OF PERIODIC TABLE TRENDS AND PATTERNS ON PERIODIC TABLE

18. INFORMATION IN THE PERIODIC TABLE Name of the Element Symbol for the Element Atomic Number:  Number of protons All atoms on the periodic table are neutral Atomic Mass:  The average mass of the isotopes of an element  Protons + Neutrons

19. SYMBOLS One or two letters that represent an element  Calcium is Ca 1.First letter is Capital 2.2nd (& 3rd) letter is Lower case 3.All letters are PRINTED only

20. STRUCTURE AND ARRANGEMENT MENDELEEV Grouped elements with similar properties. Left gaps for what he assumed were undiscovered elements. Periodic Law:  Elements exhibited a periodic recurrence of properties when arranged in order of increasing atomic mass. CURRENTLY Elements are arranged by increasing atomic number

21. Rows (Periods) Column (Groups) Families

22. Except Hydrogen  Better placed in group 7A.  Some books place it in both ELEMENTS IN SAME GROUP SHARE SIMILAR PROPERTIES

24. TRENDS AND PATTERNS ON THE PERIODIC TABLE STRUCTURE OF THE ATOM INFORMATION GIVEN BY THE PERIODIC TABLE TRENDS AND PATTERNS ON PERIODIC TABLE

25. Roughly 80% of all elements Located left of the stair-step line All metals have similar properties  Good conductors  Reactive  Usually make positive ions  Easily combined to make alloys METALS

26. Located right of the stair-step line All non-metals have similar properties  Generally poor conductors of heat and electricity  Are good oxidizing agents (like rust)  Form negative ions  Solid, liquid or gas at room temperature NON-METALS

27. Touch the stair-step line All properties between metals and non- metals  Often good Semi- conductors  Electrical conductivity between conductors (such as copper) and insulators (such as glass). METALLOIDS

28. ELECTRONEGATIVITY An atom’s ability to attract electrons to itself  increases across periods  decreases down groups

29. Size of an atom  Decreases across periods  Increases down groups ATOMIC RADIUS

30. Similar properties in Groups/Families PROPERTIES

31. Group 1 (except H)  All are shiny, soft metals  Highly reactive ALKALI METALS

32. Group 2  Highly reactive-  not as reactive as alkali  Very high melting point  Distinguishable by flame color ALKALINE EARTH METALS

33. Group 17  Name means “salt formers”  React with metals to form salts  Highly reactive HALOGENS

34. Group 18  Stable/non-reactive  Colorless  Odorless NOBLE/INERT GASSES

35. Group 3-12  Very hard  High melting/boiling points  High conductivity TRANSITION METALS

36. Periods 6-7  Elements 57-71 and 89-103 Removed form main body of the table so it fits on a standard page  Actinides are all radioactive  Lanthanides bond with water LANTHANIDE AND ACTINIDE SERIES

37. Group 13 is the Boron family Group 14 is the Carbon family Group 15 is the Nitrogen family Group 16 is the Oxygen family OTHER GROUPS