Chemistry Day 23 Tuesday, November 5th - Wednesday,
November 6th, 2019
Do-Now: “PT Quiz Review Do-Now” 1. Write down today’s FLT 2. What are valence electrons? 3. Identify the group number, name, and number of
valence electrons for our four main representative groups
4. Distinguish between transition metals and inner transition metals.
5. Bob says that Na has a larger atomic radius than Cl. He says this is because Cl has more protons (17 versus 11), and therefore a greater effective nuclear charge that pulls electrons in closer, resulting in Cl’s smaller radius. What is MISSING from this explanation?
6. Which has a bigger atomic radius and WHY: Na or Li? Be specific and descriptive.
7. Take a few minutes to review your explanations for ALL of your trends.
Take out your planner and ToC
FLT • I will be able to explain how anions and
cations form by completing Ions CN
Standard HS-PS1-1:Usetheperiodictableasamodeltopredicttherelativepropertiesofelementsbasedonthepatternsofelectronsintheoutermostenergylevelofatoms.
Ions
Recall
Valence Electrons
• Valence electrons (ve-s) = e-s in the outermost shell (highest s and p orbitals) that can participate in chemical bonding
Valence Electrons • Valence electrons à determine the
chemical properties of atoms • These are located in the s and p orbitals
of the highest occupied energy level
Valence Electrons • ve-s match the group number for
representative elements
Electron Dot Diagrams • Lewis Dot Diagrams =
Notation for showing the ve-s for an atom or ion – Write symbol with valence e-s
surrounding – Hund’s rule – don’t double up
until you have to X
Electron Dot Diagrams
• Ex/ • F • Ne • N
Forming Ions
Recall • Noble gases are inert gases – they are
highly unreactive • Noble gases = have eight ve-s and
completely filled outer sublevels
The Octet Rule • The Octet Rule = Elements gain or
lose e-s in order to obtain a noble gas configuration (8 ve-s or He 2ve-s) – Each noble gas (except He, which has 2) has 8
electrons in the outer level
Ions • Atoms can gain or lose electrons to form
ions – Cations = (+) charged ions
• Ex/ Ca2+ – Anions = (-) charged ions
• Ex/ F-
Cations • Metals lose their ve-s to form cations – They form the configuration of the closest noble gas
that’s smaller than them
Na 1s22s22p63s1 – 1 valence electron
• Na+1 1s22s22p6 – This is a noble gas configuration with 8 electrons
in the outer level.
Cations • Examples
– K
– Ca
– Al
Cations • Their charge should match their group
number
Subatomic Particles • Be sure to account for the change in
electron number for ions • Ex/ How many protons and electrons in…
Ca vs Ca+2
What are the e- configurations? • Examples
– K+
– Al3+
Anions • Nonmetals gain e-s to form anions
– They form the configuration of the closest noble gas that’s bigger than them
• S = 1s22s22p63s23p4 – 6 valence electrons
• S2- = 1s22s22p63s23p6 – noble gas configuration.
Anions • Examples
– Br
– O
– N
Anions • Group 7A: -1 • Group 6A: -2 • Group 5A: -3
What are their e- configurations? • Examples
– Br-
– O2-
Formation of Anions
Pair-Share-Respond1. Whatarevalenceelectrons?2. Distinguishbetweenanionsand
cations3. Howdometalsandnonmetalsform
ions?4. Statetheoctetrule5. Whatwouldbelargerandwhy:ForF-?
Chemistry Day 24 Thursday, November 6th – Friday,
November 7th, 2019
Do-Now: “Cat Inquiry Do-Now” 1. Write down today’s FLT
2. Define the terms anions and cations 3. Why do atoms form ions? 4. What ion will the Rb form? Show your work 5. Copy and complete: N has a ____ atomic radius
compared to C. Since both N and C have a principal quantum number of ___, this means that the ____ are the ____ and the e-s are at about the ____ distance from the nucleus. However, since N has ____ protons compared to C’s ____ protons, this means that the __________ between protons and e-s is stronger in ______, causing the electrons to be pulled ______ and the overall atomic radius is _______ than C’s.
6. Turn in your ToC#2 if you haven’t already. Take out your planner and ToC
Video Clip • Wewillwatchavideoclipaboutcatsandballoons
• Underneathyourdo-now…• Useyourpro-talksentenceframe“Inmyopinion…because…”tomakeapredictionaboutwhatyouTHINKwillhappen.
Video Clip • Now,writedownthreequestionsyouhaveaboutthevideo.
Video Clip • Discussyourquestionswithyourgroup.• Decideasagroupwhichquestionisthe“best”orthemostinteresting,andeveryoneshouldwriteitontheirpaper.
• Pickaquestionthatshouldbeanswerableifgivensomeadditionalevidence.
• Ifitisyourownquestion,placeastarnexttoit.
Video Clip • Now,wewillwatchavideo.• Duringthevideo,writedownoneortwopiecesofevidencethatcanhelpyouexplainwhat’shappening.
Video Clip • Usetheinformationfromthevideotoansweryourquestion.
• Useoneofthefollowingpro-talksentenceframes:– “FirstIconsidered…,then…____...Provesmyclaimbecause…”
– “Ifwelookatboth….and….Wecanseethat….”
– “Basedontheevidence,wecanconcludethat….”
FLT • I will be able to write the formulas and
describe properties of ionic compounds by completing Ionic Bonding CN
Standard HS-PS1-1:Usetheperiodictableasamodeltopredicttherelativepropertiesofelementsbasedonthepatternsofelectronsintheoutermostenergylevelofatoms.
Ionic Bonding
Recall
The Octet Rule • The Octet Rule = Elements gain or lose
e-s in order to obtain a noble gas configuration (8 ve-s or He 2ve-s)
Ions • Atoms can gain or lose electrons to form
ions – Metals lose e-s to form cations
• Ex/ Ca2+ – Nonmetals gain e-s to form anions
• Ex/ F-
Ions • What charges would the following atoms
have if they became ions? – Na – Cl – F – Ba – Ca – O
Compounds
Compounds • So far, we have been looking at atoms
by themselves • Compounds = substances made of
atoms of 2+ elements chemically combined in fixed ratios
Examples: NaCl CaF2 H2O
Mg(OH)2
Compounds • Compounds are held together by
chemical bonds such as ionic bonds, covalent bonds, and more!
CH4
Ionic Bonding
Ionic Bonding • Anions and cations are held together by
opposite charges (+ and -) • Ionic Bond = Strong electrostatic
attraction between an anion and cation
Ionic Bonding • Salts = Ionic compounds (ex/ NaCl)
– Formed through the transfer of e-s
Ionic Bonding • Also called SALTS • Made from: a CATION with an ANION
– or literally from a metal (+) combining with a nonmetal (-)
Ionic Bonding
• The metal (sodium) tends to lose its one electron from the outer level.
• The nonmetal (chlorine) needs to gain one more to fill its outer level, and will accept the one electron that sodium is going to lose.
Na Cl
Writing Formulas
Writing Formulas • Metals are always written 1st
– Ex: NaCl vs ClNa
Writing Formulas • When ions have equal and opposite
charges, they bond together in a 1:1 ratio – Ex: Na and F
– Ex: Mg and S
– Ex: Al and P
Writing Formulas • The charges of ions in a chemical
formula must always sum to 0 • What happens if the charges are not
equal and opposite? – Ex/ Calcium and Fluorine
Writing Formulas • If ions do not have the same charge, you
must find the lowest common multiple – Ex/ Ca and F
Writing Formulas • If ions do not have the same charge, you
must find the lowest common multiple – Ex/ Mg and P
Do-Now • Write the following formulas:
a. Mg and O
b. Li and F
c. Li and S
d. Mg and S
e. Ca and N
Properties of Ionic Compounds 1. Ionic solids have crystalline
structures - a regular repeating arrangement of ions in the solid
– Ions are strongly bonded together. – Structure is rigid, but brittle
Coordination Numbers:
Both the sodium and chlorine have 6
Both the cesium and chlorine have 8
Each titanium has 6, and each oxygen has 3
NaCl
CsCl
TiO2
Coordination number- number of ions of opposite charge surrounding it
Properties of Ionic Compounds 2. High melting points • It requires a lot of energy to change
from a solid to a liquid • High boiling point as well
Do they Conduct?
• Conducting electricity means allowing charges to move.
• In a solid, the ions are locked in place. • Ionic solids are insulators. • When melted, the ions can move around. 3. Melted ionic compounds are
conductors. – NaCl: must get to about 800 ºC. – Dissolved in water, they also conduct (free
to move in aqueous solutions)
Pair-Share-Respond1. Whatarecompounds?2. Definetheterm“ionicbond”3. Howareionicbondsformed?4. PredicttheformulaforAluminumand
Oxygen