4.1 Atomic Theory & BONDING

1. 4.1 Atomic Theory & BONDING

2. 4.1 VOCABULARY Covalent Compound Electrons Element Family/Group Halogens Ionic bonding Ionic compounds Ions Lewis Diagram Matter Metal Metalloids Mixture Alkali earth metals Alkali metals Anions Atomic # Atomic number Atomic Theory Atoms Bohr diagram Cations Chemical Change Chemical reaction Compound Covalent bonding Molecule Neutron Noble gases Non-Metal Nucleus Period Proton Pure Substance Stable outer shell Subatomic particle Transition metals Valence electrons

3. MATTER Mixtures Pure Substances Compounds Solutions Elements Mechanical Suspensions

4. CHANGES IN MATTER PHYSICAL CHANGE CHEMICAL CHANGE No new substances produced New substances produced Very hard to reverse Only a change in state or appearance = CHEMICAL REACTION

5. ATOMS • An atom is the smallest particle of an element that still has the properties of that element • 50 million atoms, lined up end to end = 1 cm • An atom = proton(s) + neutron(s) + electron(s) See pages 168 - 169 (c) McGraw Hill Ryerson 2007

6. COMPOUNDS • Atoms join together to form compounds • A compound is a pure substance that is composed of twoor more atoms combined in a specific way. • Oxygen and hydrogen are atoms/elements; H2O is a compound. (c) McGraw Hill Ryerson 2007

7. COMPOUNDS

8. CHEMICAL CHANGE A chemical change occurs when the arrangement of atomsin compounds changesto form new compounds. (c) McGraw Hill Ryerson 2007

9. ATOMIC THEORY • Atoms are made up of smaller particles called subatomic particles. See page 170 (c) McGraw Hill Ryerson 2007

10. ATOMIC THEORY • The nucleus is at the center of an atom • The nucleus is composed of -positive protons and neutral neutrons • Electrons exist in the space surrounding the nucleus. See page 170 (c) McGraw Hill Ryerson 2007

11. ATOMIC THEORY • # of protons = # of electrons in every atom • Nuclear charge = charge on the nucleus = # of protons • Nuclear charge = Atomic number • Atomic number = # of protons = # of electrons See page 170 (c) McGraw Hill Ryerson 2007

12. INCREASING REACTIVITY

13. Elements • Atomic Number = smaller number • = number of p+ and e- • Atomic Mass = larger number • = total of p+ and n0 Atomic Number • +2 • +3 • Ni • Nickel • 58.71 Combining Capacities Symbol Name of Element Atomic Mass

14. Calculating Number of subatomic particles • Protons = same as atomic number • Electrons = same as atomic number • Neutrons = subtract atomic number from atomic mass

15. Periodic Table Practice

16. INCREASING REACTIVITY The Periodic Table • Where are the following? • Atomic number • Atomic Mass • Charges • Symbol • Name See page 172 (c) McGraw Hill Ryerson 2007

17. Organization of the Periodic Table • In the periodic table elements are listed in order by their atomic number. • Metals are on the left • The transition metals range from group 3 -12 • Non-metals are on the right • Metalloids form a “staircase” toward the right side. See page 171 (c) McGraw Hill Ryerson 2007

18. Metals (left of zigzag line) Physical Properties of Metals: Shiny, good conductors of heat and electricity, ductile (make wires) and malleable (thin sheets). Easily lose electrons. Like to join with non-metals. Corrode (tarnish/rust). Nonmetals (right of zigzag line) Physical Properties of Nonmetals: dull appearance, poor conductor, brittle (breaks easily), not ductile or malleable. Easily gain electrons. Like to join with metals, but will bond to other non-metals. Metalloids (on both sides of zigzag line) Physical Properties of Metalloids: have properties of both metals and nonmetals. Solid, shiny or dull, ductile and malleable, conduct heat and electricity, but not very well.

20. INCREASING REACTIVITY The Periodic Table • Where are the following? • Metals • Non-metals • Transition metals • Metalloids See page 172 (c) McGraw Hill Ryerson 2007

21. Organization of the Periodic Table • Rowsof elements (across) are called periods. • All elements in a period have their electrons in the same general area around their nucleus. • Example: period 3 all have 3 electron shells sodium magnesium aluminum See page 171 (c) McGraw Hill Ryerson 2007

22. Organization of the Periodic Table • Columns of elements are called groups, or families. • All elements in a family have similar properties and bond with other elements in similar ways. • Group 1 = alkali metals • Group 2 = alkaline earth metals • Group 17 = the halogens • Group 18 = noble gases 18 17 See page 171 (c) McGraw Hill Ryerson 2007

23. Organization of the Periodic Table Group 1 = alkali metals very reactive metals want to give away 1 electron ie: lithium, sodium, potassium... 18 1 2 17 See page 171 (c) McGraw Hill Ryerson 2007

24. Organization of the Periodic Table Group 2 = alkali earth metals somewhat reactive metals want to give away 2 electrons ie: beryllium, magnesium, calcium... 18 1 2 17 See page 171 (c) McGraw Hill Ryerson 2007

25. Organization of the Periodic Table Group 17 = halogens very reactive non-metals want to accept 1 electron react with alkali metals ie: fluorine, chlorine, bromine...... 18 1 2 17 See page 171 (c) McGraw Hill Ryerson 2007

26. Organization of the Periodic Table Group 18 = noble gases STABLE. Very non reactive gaseous non-metals ie: helium, neon, argon...... 18 1 2 17 See page 171 (c) McGraw Hill Ryerson 2007

27. INCREASING REACTIVITY The Periodic Table • Where are the following? • Period • Group/Family • Alkali metals • Alkaline earth metals • Halogens • Noble gases See page 172 (c) McGraw Hill Ryerson 2007

28. Periodic Table & Ion Formation • Atoms gain and lose electrons to form bonds. • The atoms become electrically chargedparticles called ions. See page 173 (c) McGraw Hill Ryerson 2007

29. Periodic Table & Ion Formation • Atoms gain and lose electrons to form bonds. • Metals lose negative electrons & become positive ions. • Positive ions are called CATIONS. See page 173 (c) McGraw Hill Ryerson 2007

31. Periodic Table & Ion Formation Some metals are MULTIVALENT and can lose a varying number of electrons. For example, iron, Fe, loses either two(Fe2+) or three (Fe3+) electrons See page 173 (c) McGraw Hill Ryerson 2007

32. Periodic Table & Ion Formation • Atoms gain and lose electrons to form bonds. • Non-metals gain electronsand become negative ions • Negative ions are called ANIONS See page 173 (c) McGraw Hill Ryerson 2007

33. Periodic Table & Ion Formation Atoms gain and lose electrons in an attempt to be STABLE. The noble gases are stable because they have FULL outer shells of electrons. They don’t need to lose or gain any e-s. Atoms in each period want to have the same number of electrons in their outer shell (VALENCE ELECTRONS) as the noble gases on the end of their period. See page 173 (c) McGraw Hill Ryerson 2007

34. BOHR MODELS • Bohr diagrams show how many electrons appear in each electron shell around an atom. • The first electron shell holds 2 electrons • The second electron shell holds 8 electrons • The third electron shell holds 8 electrons • The fourth electron shell holds 18 electrons • The noble gas elements have full electron shells and are very stable= STABLE OCTET See page 174 (c) McGraw Hill Ryerson 2007

35. Patterns of Electron Arrangement in Periods & Groups • Electrons appear in shells in a very predictable manner. • The period number = the number of shells in the atom. • Except for the transition elements (family 3-12), the last digit of the group number = the number of electrons in the valence shell. See page 175 (c) McGraw Hill Ryerson 2007

36. BOHR MODELS • It has 2 + 8 + 8 = 18 electrons, and therefore, 18 protons. • It has three electron shells, so it is in period 3. • It has eight electrons in the outer (valence) shell. What is the Bohr Model Diagram for Argon? See page 174 (c) McGraw Hill Ryerson 2007