Warmup - do this on a left-hand page What is the most active metallic element? List the elements of Group 17 in order of increasing atomic radius. What one characteristic is shared by all of the elements in Group 16? (Note: you don’t need any information other than the periodic table for this) If an element can form various cations, is an excellent electrical and thermal conductor, and has a high melting point, what group is it from? (Note: alkali metal, alkaline metal, transition metal, halogen, noble gas)

We will learn about bonding. I will complete a foldable and use dot diagrams to illustrate bonding. Success Criteria Know when the bond will be ionic and when it will be covalent. Know the difference between an ionic bond and a covalent bond. Be able to use dot diagrams to illustrate bonding.

Housekeeping Missing work listed on the next slide. All missing work must be turned in by Friday, 12/2. After that, it will remain a zero. If I do NOT have the assignment from you, your name will be in red. Only a few people have turned in the Periodic Trends assignment. The names of those who HAVE turned it in are in black.

Warmup answers What is the most active metallic element? Francium List the elements of Group 17 in order of increasing atomic radius and explain the trend. F, Cl, Br, I, At The radius increases as you go down the group BECAUSE the number of energy levels increases, so the outer electrons are shielded from the pull of the protons and are farther out.

Warmup Answers 3. What one characteristic is shared by all of the elements in Group 16? (Note: you don’t need any information other than the periodic table for this) They all have the same number of valence electrons, 6. 4. If an element can form various cations, is an excellent electrical and thermal conductor, and has a high melting point, what group is it from? (Note: alkali metal, alkaline metal, transition metal, halogen, noble gas) Transition metal

Trend and Reason Study the trends and reasons for the trends that I am passing out. After the retest, tape this into your notebook. Tape it only on one end, so you can flip it up to see the other side. Put it on the same page as your notes for the periodic table.

Trend and reason Lowest group Highest group Exception Ionization energy across a period Increases as you go to the right BECAUSE the number of protons increases, so the stronger attractive force holds the electrons tighter Alkali, because they have the fewest protons in the period (smallest magnet) Noble Gases, because they have a complete valence shell (Fort Knox) None Electro- negativity across a period Increases as you go to the right BECAUSE the number of protons increases, so the stronger attractive force can more easily attract electrons Halogens because they have more protons than the other groups (bigger magnet) Noble Gas has very low electronegativity because they have a complete valence shell Atomic radius across a period Decreases as you go to the right BECAUSE the number of protons increases, so the stronger attractive force pulls the electrons in tighter. Noble Gases, because they have most protons in the period (biggest magnet)

Trend and reason Lowest period Highest period Ionization energy down a group Decreases as you go down BECAUSE the number of energy levels increases, so the outer electrons are shielded from the protons and causes a weaker attractive force Period 7 because it has more energy shells, so the outer electrons are shielded from the attractive force of the protons. Period 1 because it has the fewest energy shells, so the attractive force is the strongest. Electro- negativity down a group Decreases as you go down BECAUSE the number of energy levels increases, so the outer shell is shielded from the protons and causes a weaker attractive force Atomic radius down a group Increases as you go down BECAUSE the number of energy levels increases, so the outer shell is shielded from the protons and the weaker attractive force causes the electrons to spread out more Period 1 because it has the fewest energy shells, so the outer electrons are affected by the full attractive force of the nucleus. Period 7 because it has the most energy shells, so the outer electrons spread out due to the weaker attractive force caused by the shielding of the inner electrons.

New section for your notes Bonding

Ions Ion - an element with a charge from gain/loss of electrons. cation: + charge, loses e_ anion: - charge, gains e_

Atoms only want one thing Atoms want to be like a noble gas: 8 valence electrons in valence shell - Octet Rule Can give or take electrons to get full valence shell No charge 2 valence electrons ONLY for H and He - Duet Rule

Chemical Bonding Chemical bond - mutual electrical attraction between nuclei and valence electrons of different atoms bonded together Makes atoms more stable

Ionic Bonds Definition - ions transfer electrons to form a bond Occurs Between - metal and nonmetal END - big difference (nonmetal steals metal’s valence e-)

Bonding Foldable Tape the pages at the top like a hinge. First tape down the Ionic Formulas/Dot Diagrams page with Ionic Formulas facing up. Then tape Chemical Bonding/Ionic Bonding with Chemical Bonding facing up slightly higher on the page.

Fill out the chart and then glue into your notebook on a left-hand page.

Covalent Bonds Definition - ions share electrons to form a bond Occurs Between - nonmetal and nonmetal END - small difference (too weak to steal, have to share)

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