Do Now: Record and Answer the following questions in your notebook
1.What is the reactivity trend within group 1?
2. Which element has chemical properties that are most similar to those of calcium?
(1) Co (2) K (3) N (4) Sr
3. What is the reactivity trend within group 17? .
Aim: : Can you explain the trends in atomic radius across and down the periodic table?
*Puzzle: Use the name of an element to solve the puzzle.
“A fur Seller”
Periodicity
What trend did we look at yesterday?
• REACTIVITY
• Metallic / Non-metallic Character
• Atomic Radius
• Ionization Energy
• Electronegativity
Trends that exist across and down on the Periodic Table
Reel Big Fish- Trendy
Atomic Radius
• Definition-
• The distance between the center of two atoms connected divided by 2.
•Good measure of the size of an atom
Why does this trend occur?
-Increases down a
group
Why do these trends occur?
• Decreases across a period
Student Explanation: because there are more protons so the electrostatic attraction between the protons in the nucleus and the electrons is stronger making our atom smaller.
Atomic Radii Trends
LEFT RIGHT Atomic Radius DECREASES TOP BOTTOM Atomic Radius Increases
Atomic Radius Trend
Largest elements on lower lef Smallest elements upper right
Reflection
• Look at your notes and think about the lesson.
Write a two to three sentence summary of the
lesson in your notes
Exit Slip Exit Slip
Explain the trends in atomic
radius across and down the
PT
Do Now: Record and Answer the following questions in your notebook
1.Which metal atom on the periodic table loses electrons most easily?
2.Which non metal atom on the periodic table gains electrons most easily?
3.Why does an elements atomic radius decrease across a period?
4.Why does an elements atomic radius increase going down a group?
Aim: : Can you explain the trend in ionization energy across and down the periodic table?
*Puzzle: Use the name of an element to solve the puzzle.
“A fur Seller”
Review Ionization Energy Practice
Ionization Energy
• Definition-
• The amount of energy needed to remove the outermost electron from a neutral atom.
X + energy X
++ 1 electron
1
stIonization Energy Trend
Highest ionization energy elements are on the upper right Lowest ionization energy elements are on the lower lef
High Ionization Energy
(fill in the blank)
• High ionization energy values indicate a _________ hold on electrons.
• A really High ionization energy means the
element would rather __________electrons?
Low Ionization Energy
(fill in the blank)
• Low ionization energy values indicate a ___________hold on electrons.
• A very low ionization energy means the
element will easily _________ electrons.
Learning Check:
High ionization energy values indicate a strong hold on electrons Low ionization energy values indicate a weak hold on electrons
If an atom has a high ionization energy, what do we know about its ability to lose or gain
electrons?
If an atom has a low ionization energy, what do we know about its ability to lose or gain
electrons?
Learning Check
1.Which has the smallest ionization energy He, N, Na? Why?
Explain in terms of hold on electrons
and atomic size.
Reflection
• Look at your notes and think about the lesson.
Write a two to three sentence summary of the
lesson in your notes
Practice – Handout on
Ionization Energy
Refelction Refelction
Answer the aim in two
sentences in your notes
Exit Slip Exit Slip
Explain the trend in
ionization energy across and
down the periodic table.
PT CLASSWORK : green workbook p. 50: Q 17 – 21, 24, 25 (14mins)
p. 44: Q 8-11p. (8mins) p. 48: 12-20 (9mins)
p. 49/50: Q 1-5, 9-11,15,16 (20mins) Please follow these Directions:
Complete the following question on a loose leaf. Be sure to write the correct heading.
Read the question. Identify key words by writing the key words down then annotate the key words.
Finally answer the question by writing out the correct answer choice for MC Q’s or writing a response for the Short Answer Q’s.
Review Quiz
Do Now: Record and Answer the following questions in your notebook
Aim: : Can you explain the trend in
electronegativity across and down the periodic table?
*Puzzle: Use the name of an element to solve the puzzle.
“Not an exciting person”
Do Now:
Record and answer the following in your notebook.Which group of circles, when
considered in order from the top to the bottom, best represents the
relative size of atoms of Li, Na, K, and Rb, respectively?
What did we learn yesterday?:
1.Which has the smallest ionization energy Kr, Li, Be? Why? Explain in
terms of hold on electrons and atomic
size.
Recap:
Each element in a group has similar chemical properties because of the same number of valence electrons.
Metal elements lose electrons and we can tell how metallic/active an element is by looking at its ability to LOSE electrons.
(amount of electrons and electrostatic attrition)
Non-metals elements gain electrons and we can tell how active they are by looking at their ability to GAIN electrons.
(amount of electrons and electrostatic attrition)
Electronegativity
• Definition-
• measure of an element’s attraction for electrons when bonded to another atom.
• Scale created by Linus Pauling
Scale is from 0.7 - 4.0
4.0 is the highest attraction for electrons
0.7 is the lowest attraction for electrons
• Values can be used to predict the type of bond that will form between elements
Electronegativity Trend
Most electronegative elements are on upper right Least electronegative elements are on lower lef
Electronegativity Trends
Lower Lef Upper Right Electronegativity Increases
Regents Questions Practice
1. Which three groups of the Periodic Table contain the most elements classified as metalloids
(semimetals)?
(1) 2, 13 & 14 (2) 14, 15 & 16 (3) 16, 17 & 18
2. Which element in Group 15 has the strongest metallic character? Why?
Bi, As, P, N
3. Order the following elements according to metallic
character (most to least) and explain why with reference to energy levels and hold on electrons. Li, I, K, F
Essential Questions:
Start of Classwork (CW8)
1. Which element in Group 2 has the strongest metallic character? Why? Use at least two examples to explain.
2. What happens to the atomic radius of the
following elements as you go across the periodic table and why? Be, B, F
Green work book Page 49 Q 1-8 and 14-16
Classwork 8 Cont.
• Green work book Page 49 Q 1-8 and 14-16
• On a lose leaf write the Question number with correct answer choice and answer choice
number with a short reason.
• * Super Stars Q 21 - 25
Practice 14 – Handout on Electronegativity
and PROJECTS!
Do Now: Record and Answer the following questions in your notebook
1. Write down your definition of an ion.
2. What is the difference between an atom, an ion and an excited state atom. Use Calcium as an
example and draw pictures.
Aim: : How do we explain the trend in ionic
radius verses atomic radius?
• Atoms gain or lose electrons to become charged
Ions
particles called: ions.
• Metals lose valence electrons to become positive ions (cations)
• Nonmetals tend to gain valence electrons to become negative ions (anions)
• As these atoms gain or lose electrons, they complete an octet of valence electrons or a full shell
1. What ions will the following atoms form? Explain why.
Li, S, Br, F
How can we tell what ions will
form from a specific atom?
Ionic Radius
Definition- Distance from the nucleus to the outer energy level of the ion.
• When an atom loses its valence electrons, it loses the outer energy level and its radius decreases.
• When an atom gains valence electrons its radius increases.
• Be able to compare the ion size to the neutral atom size.
(eg. Na atom compared to Na+1 ion)
1. Metallic ion is always ____________than the metal atom it is formed from.
2. Nonmetallic ion is always ___________than the nonmetal atom it is formed from.
Ionic Radius
LearningCheck
1. Which is bigger an atom of sodium or an atom of Francium and why?
2. Which is bigger an ion of chlorine or an atom of Cl?
3. Which is smaller an ion of Mg or
and atom of Mg?
Summary
Aim: What is the trend in metallic character on the periodic table?
Do Now: record and answer the following in your notes.
1. What happens to the atomic radius of the
following elements as you go across the
periodic table and why? Be, B, F
Lets take 3 metals in Group 1 to use as examples to explain
metallic character….
Lets take 3 non-metals in Group 17 to use as examples to explain non-
metallic character….
Learning Check
1. Which element in period 2 of the periodic table is the most reactive non-metal?
(1) C (2) O (3) N (4) F
Metallic / Non-metallic Character
Most metallic elements are on the lower lef Least metallic elements are in the upper right
