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Transcript of Agenda: Warm-up: Properties of Groups Trends in properties How do we use the Periodic Table to...
Agenda:
Warm-up: Properties of Groups
Trends in properties How do we use the Periodic Table to predict properties of elements?
Reactivity: Atomic size Ionization EnergyElectronegativity
Return Test
Homework:
Objective: To understand the physical and chemical properties of atoms based on their position on the Periodic Table
Next Unit is forming bonds and compounds based on reactivity
Warm-up: Properties of Groups • Alkali Metals, Halogens, Noble Gases
• Which group is the least reactive? • In Group 1, which elements are most reactive? Why?• In Group 17, which elements are most reactive? Why? • Which Group contains all gases? • Which group always forms ionic compounds? • What other properties change in a Group when going
down the PT?
Predicting how easily an element reacts
What characteristics of an element impact how easily it reacts with other elements to form a chemical compound?
The electron arrangement of each atom determines its chemical behavior (how it reacts and bonds).
1. Forming ions based on number of valence electrons
2. Atomic size
3. Ionization energy
4. Electronegativity
Atoms lose, gain or share valence electrons in order to be stable like the Noble Gases.Metals will: Non-metals will:
Forming Compounds
• Ions come together to form a ______________ ______________ .
• Many formula units are held together to make an _______ compound.
PERIODIC TRENDSUSING THE PERIODIC TABLE TO PREDICT PROPERTIES OF ELEMENTS AND GROUPS
Focus on Reactivity
Atomic size
Ionization Energy
Electronegativity
Atomic Radii
• Atomic Radius – measurement of the size (volume) of the atom
• Defined by the edge of its orbital but since the edges are fuzzy, difficult to determine
• Atomic Radii – half the distance between the nuclei of identical atoms that are bonded together
Ionization Energy
• Ionization energy – the energy required to remove one electron
X + energy X+ + e-
• An electron can be removed from an atom if enough energy is absorbed (+) by the atom
• Note: measurements of this are made on individual atoms in gas phase to avoid interactions with nearby atoms
Adding energy = Endothermic
How do metal atoms lose electrons? Ionization energy
• Ground State, Excited State, Ionization energy
Lithium
Electronegativty
•Electonegativity: An atoms’ ability to attract electrons from another atom
•Electron Affinity: The energy released when an electron is added to an atom
X + e- X- + energy
Releasing energy = Exothermic
How do non-metal atoms gain electrons? Electronegativity
• Large non-metal Small non-metal atomatom
Examining properties & trends• Use Interactive Periodic Table –http://www.ptable.com/• Click on Properties
• Work in pairs• Each person completes the table
• When completed, investigate the properties of the transition metals
• Homework: Summary on a separate paper• Define the property• Summarize its trends: across periods and down groups• Summarize the characteristics of the property in each of the 3
groups studies
Linking Electron Arrangement to the PT
• Use Interactive Periodic Table –http://www.ptable.com/• Click on Orbitals
S P D F blocks
Which are being filled?
Noble Gas Notation – using the PT
Rules for Group 1 & Group 2
Periods ?
Rules for Groups 13-18
Periods?
Rules for Transition Metals
Period ?
7. Reactivity
Group 18 (called the _______________) are ____________ (also called ________ or _____________), because:
Group 1 (called ____________) are the most reactive metals because:
Group 17 (called ___________) are themost reactive nonmetals because:
1 18
2 13 14 15 16 17
3 4 5 6 7 8 9 10 11 12
Trends for Ionization Energy & ElectronegativityArrows to show trends for metals & non-metals
Reactivity: trends for metals and non-metals
Predicting Properties of Elements- based on the position on the Periodic
Table : Size; IE; EN
Property: which element has the largest value?Ca vs. Br C vs. Sn F vs. I Si vs. ClNa vs. P Li vs. KBe vs. O S vs. ArAl vs. S Ne vs. KrB vs. Al B vs. Ne
Periodic Trend Animation • http://faculty.ucc.edu/chemistry-pankuch/Amin.html• Atomic size
• Ionic size Interactive animations• Ionization • Electronegativity
• For later used: bond formation
Periodic Table
• Objective: To understand the physical and chemical properties of atoms based on their position on the Periodic Table
• NC Essential Standards 1.3
• Physical properties:
• Chemical properties:
Periodic Tables • Groups • Http://www.ptable.com/Images/periodic%20table.png
• Interactive Periodic Table – useful for trends of properties• http://www.ptable.com/
PERIODIC TRENDSUSING THE PERIODIC TABLE TO PREDICT PROPERTIES OF ELEMENTS AND GROUPS
Focus on Reactivity
Atomic size
Ionization Energy
Electronegativity
Electron Affinity
Atomic Radii
• Atomic Radius – measurement of the size (volume) of the atom
• Defined by the edge of its orbital but since the edges are fuzzy, difficult to determine
• Atomic Radii – half the distance between the nuclei of identical atoms that are bonded together
Atomic Radii
• Across Period:• atoms get smaller• because of the increased number of protons attracting the electrons
• the electrons added in the same energy level do not shield electrons from nuclear charge
• Down Group:• atoms get larger• increases• because the energy levels being added to the atom
Atomic/Ionic Radii
Ionization Energy
• Ionization energy – the energy required to remove one electron
X + energy X+ + e-
• An electron can be removed from an atom if enough energy is absorbed (+) by the atom
• Note: measurements of this are made on individual atoms in gas phase to avoid interactions with nearby atoms
Ionization Energy
Ionization Energy• Across Period:
• requires more energy to remove an electron so increases
• because electrons added in the same energy level do not shield electrons from nuclear charge
• Down Group:• requires less energy to remove electron so decreases
• because the valence electrons are farther away from protons attracting them
Ionization Energy
Ionization Energy
Electronegativty• Ability to attract electrons
• Non-metals (excluding Noble Gases)• High electronegativity
Electronegativity
• Across Period:• Increases
• Non-metals attract electrons
• Smaller atoms
• Down Group:• Decreases
• Protons in the nucleus are shielded by inner energy levels
• Harder to attract electrons
Electronegativity
Periodic Trend Animation • http://faculty.ucc.edu/chemistry-pankuch/Amin.html• Atomic size• Ionic size Interactive animations• Ionization • Electronegativity
• For later used: bond formation
1 18
2 13 14 15 16 17
3 4 5 6 7 8 9 10 11 12
Trends for Ionization Energy & ElectronegativityArrows to show trends for metals & non-metals
Reactivity: trends for metals and non-metals
6. Octet Rule
Atoms tend to ______, ______, or _______electrons in order to have _____ valence
electrons._______ valence electrons gives stability.
Exception:
Duet rule: Hydrogen
7. Reactivity
Group 18 (called the _______________) are ____________ (also called ________ or _____________), because:
Group 1 (called ____________) are the most reactive metals because:
Group 17 (called ___________) are themost reactive nonmetals because:
1 18
2 13 14 15 16 17
3 4 5 6 7 8 9 10 11 12
Trends for Ionization Energy & ElectronegativityArrows to show trends for metals & non-metals
Reactivity: trends for metals and non-metals
Predicting Properties of Elements- based on the position on the Periodic
Table : Size; IE; EN
Property: which element has the largest value?Ca vs. Br C vs. Sn F vs. I Si vs. ClNa vs. P Li vs. KBe vs. O S vs. ArAl vs. S Ne vs. KrB vs. Al B vs. Ne
Periodic Table videos• New Periodic Table Song• http://www.youtube.com/watch?v=IsBZx0tv6dQ• Prism website• http://www.gk12.ilstu.edu/chemistry/index.asp?page=perio
dicTable