Today’s Do Now 9/19/ Which is an anion? Na +1 or S How many electrons does the ion Cl - have? 3. When Oxygen forms an ion, what charge will it most likely have? How do you know?

By the end of class today I will be able to… Identify, define, and explain the periodic trends of atomic radii, ionic radii, electronegativity, and ionization energy

Periodic Trends

Periods = Rows Side to Side

Group = Column = Family Up and Down

Keep in Mind The trends that we talk about today only apply to the Main Groups 1, 2, 13, 14, 15, 16, 17,18

HOW DO YOU TREAT THE THINGS YOU VIEW AS PRECIOUS? What is “precious” to you?

Electrons are Precious to Atoms

Today’s Game Plan Do Now10 minutes Atomic Radius & Electronegativity 15 minutes Element War10 minutes Ionic Radius & Ionization Energy 15 minutes Summing it up15 minutes Practice15 minutes Closing & Exit Ticket10 minutes

Atomic Radius – size of an atom Distance between the two nuclei of two identical atoms  2

Atomic Radius – size of an atom Decreases across a period Increases down a group Why? The electrons are being added to the same energy level, but the number of protons in the nucleus increases Why? The outermost electron is in a higher energy level, which is further from the nucleus, so the radius increases

Atomic Radius – size of an atom Largest atoms are in the lower left Smallest are in the upper right

Electronegativity – tendency of an atom to attract shared electrons towards itself “Greediness” of an atom

We wants it! We needs it! Must have the precious!

Electronegativity Increases across a period Increases up a group As the size of the atom decreases, the electronegativity increases

Electronegativity Highest Lowest Most electronegative in top right of table (F, O, N) Least electronegative in bottom left of table

Today’s Game Plan Do Now10 minutes Atomic Radius & Electronegativity 15 minutes Element War10 minutes Ionic Radius & Ionization Energy 15 minutes Summing it up15 minutes Practice15 minutes Closing & Exit Ticket10 minutes

Element War Shuffle Element Cards and deal out all cards to players Play will begin with the player with the longest hair and play will continue clockwise Player with the card with the largest atomic radius will take the trick Player with the most tricks at the end of the round wins

Element War Shuffle Element Cards and deal out all cards to players Play will begin with the player with the longest hair and play will continue clockwise Player with the card with the largest electronegativity will take the trick Player with the most tricks at the end of the round wins

Today’s Game Plan Do Now10 minutes Atomic Radius & Electronegativity 15 minutes Element War10 minutes Ionic Radius & Ionization Energy 15 minutes Summing it up15 minutes Practice15 minutes Closing & Exit Ticket10 minutes

Ionic Radius Ionic radius – the distance from the nucleus to the outermost electron of an ion Cations are always smaller than their parent atom  Why? – they have fewer electrons than protons so the electrostatic attraction is greater

Ionic radius Anions are always larger than their parent atom  Why? – they have more electrons than protons

Ionic Radius Cations and anions decrease in size across a period  Why? – the number of positively charged protons increase, the valence electrons are still the same distance away from the nucleus Cations and anions increase in size down a group  Why? – the outmost electrons occupy energy levels farther from the nucleus

DECREASE INCREASE

IONIZATION ENERGY The energy required to remove an electron from an atom

Electronegativity vs. ionization energy Electronegativity = Greediness for something shared Ionization energy = stinginess for something already in your possession

Ionization energy Ionization energy increases across a period  Why? – valence electrons are more tightly bound and it takes more energy to remove an electron Ionization energy increases up a group  Why? – the atomic radii decreases as you go up a group, so the attraction between valence electrons and the protons increases and it takes more energy to remove an electron

Today’s Game Plan Do Now10 minutes Atomic Radius & Electronegativity 15 minutes Element War10 minutes Ionic Radius & Ionization Energy 15 minutes Summing it up15 minutes Practice15 minutes Closing & Exit Ticket10 minutes

Complete the table with your groups Definition Trend Across Period Why? Trend Down Group Why? Element to reference Atomic Radius Electronegativity Ionic Radius Ionization Energy

Today’s Game Plan Do Now10 minutes Atomic Radius & Electronegativity 15 minutes Element War10 minutes Ionic Radius & Ionization Energy 15 minutes Summing it up15 minutes Practice15 minutes Closing & Exit Ticket10 minutes

Independent practice Periodic Trends Worksheet – must be done independently and silently

Today’s Game Plan Do Now10 minutes Atomic Radius & Electronegativity 15 minutes Element War10 minutes Ionic Radius & Ionization Energy 15 minutes Summing it up15 minutes Practice15 minutes Closing & Exit Ticket10 minutes

Homework Complete worksheet Complete review packet