Catalyst – Review Day 2 1. What is the difference between an independent and dependent variable? 2. What are the 2 main subgroups of matter? Please take out your HW!

Today’s Agenda  Catalyst  Go over Review HW Packet #1  Review the Atom  Individual Work Time  Whiteboards??  Exit Question

Today’s Objectives  SWBAT master the ATOM! (Unit 3)

Bring it together…  Yesterday we talked about matter…  If you keep breaking down matter further and further, you will get to something called the… ATOM!! For more on the theories, go to the book and read….

Subatomic Particles  What are the three subatomic particles?  Protons, Neutrons, and Electrons  How do you know how many there are in each atom?  Protons= atomic number (ID number)  Electrons= atomic number (if atom is neutral)  Neutrons= mass number- atomic number

Wow… that’s pretty fantastic  I wonder if there is anything else that we can get from the periodic table…  TOTALLY MAN!  Atomic Radius! – size of the atom  Ionization energy! – how much energy it takes to remove one electron!  Electronegativity! – how much an atom wants electrons

Atomic size DECREASES as you go across the Periodic Table Atomic size INCREAESES as you go down thePeriodic Table

Electronegativity Trends

Practiz 1. Which element has the highest 1 st ionization energy?  Boron, Carbon, Nitrogen, or Oxygen 2. Which element has the lowest atomic radius?  Lithium, Sodium, Potassium, or Rubidium 3. Which element has the highest electronegativity?  Oxygen, Sulfur, Selenium, or Tellurium

Man, what a rush!  Can we please, please, please talk about ionic bonding?  Fiiineeeee…..  What do you have to do to get the formulas for ionic compounds?

Kris Kross Method! Ca 3 As 2 Ca 2+ As 3-

Then, what do you do?  Name the sucka!  Since you had to do a lot of work, all you do for naming is…  Change the second element’s ending to –ide.  For polyatomics, just use the name.  Ex:  MgCl 2 = Magnesium Chloride  Al(OH) 3 = Aluminum Hydroxide

Wow, too easy for comfort…  What about covalent bonds?!!?!?!? I love them…  Well, no kriss krossing… you will be given the formula.  But, naming is a tad bit trickier.

Naming Covalent Compounds N2ON2O

Rule 1: If the first element has more than one atom, give it a prefix.

Naming Covalent Compounds N 2 O Dinitrogen

Naming Covalent Compounds Rule 2: the second element gets a prefix, uses the root of the word and ends in -ide.

Naming Covalent Compounds N 2 O Dinitrogen Monooxide

Naming Covalent Compounds Rule 3: the “o” or “a” at the end of the prefix is dropped if the element begins in a vowel.

Naming Covalent Compounds N 2 O Dinitrogen Monooxide

Naming Covalent Compounds N 2 O Dinitrogen Monoxide

Writing Formulas from Names Is it ionic or is it covalent? EXAMPLES Carbon tetrachloride Diarsenic trioxide Magnesium hydroxide Calcium Chloride YOUR TURN TO “FORMULIZE” 1. Sulfur trioxide 2. Carbon monoxide 3. Lithium Oxide 4. Rubidium Phosphate 5. Tetraphosphorus hexasulfide 6. Xenon difluoride

Periodic Table Whiteboards!  Put a box around all Alkali Metals  Put a box around all Halogens  Put a box around all Transition Metals  Put a box around all Noble Gases  Circle the MOST ELECTRONEGATIVE element  Circle the LEAST ELECTRONEGATIVE element

Periodic Table Whiteboards!  Circle the element with an ATOMIC NUMBER of 7  Circle the element with 14 PROTONS  Circle the element with an ATOMIC MASS of 52  Circle the element with 45 ELECTRONS  Circle the element with 20 PROTONS and 20 NEUTRONS

Exit Question 1. Pick the most electronegative element of these two: Sodium or Magnesium. 2. Pick the element with the higher 1 st ionization energy: Fluorine or Oxygen. 3. Now write the formula and name the compound formed between lithium and oxygen. 4. Name SO 2.

 Atoms (subatomic particles)  Ionic Bonding… naming  Covalent Bonding… naming  Ionization Energy  Electronegativity