23-24 Unit 3 Lesson 5: Periodic trends

​Tuesday : Periodic Trends

• Wed 10/4- Unit 3 quiz

• Mon 10/9 Unit 3 test

• Thurs 10/12 -Benchmark 1 on Units 1-3 (end of Q1)

• Fri 10/13- NO SCHOOL, TWD

Announcements/Reminders​

Bellwork:

​

Agenda

​

• Finish graphs (10 minutes)- due at 11:59PM

• Oxidation states review

• Periodic trends

• Complete pages 12-14 in the workbook for HW.

1. form on GC

​Wed 10/4- Unit 3 quiz- 20 MC

• History/arrangement of PT

• prop. of metals/non-metals

• oxidation states

• families

“Happy” Elements

•All elements want to be
“happy”
•https://youtu.be/C7dPqrmDWxs

•An atom wants a stable
outer energy level to
make them “happy”

Octet Rule

•Atoms will form bonds with other atoms in

order to have eight valence electrons.

• Can share or transfer electrons with other

elements

• Elements will not just lose or gain electrons. They will

give to another element or take from another element

Multiple Choice

What is the oxidation number of Na in Na⁺ ?

• 0

• +1/2

• +1

• -1

Multiple Choice

How many valence electrons do elements in Group 15 have?

• 15

• 5

• 4

Multiple Choice

How many electrons are required to fill the outer shell for elements in Group 15

• 15

• 3

• 5

Multiple Choice

How many valence electrons are required to fill the outer shell for elements in Group 17?

• 17

• 1

• 7

Multiple Choice

What is the charge, or oxidation number, for elements in Group 17?

• + 1

• -7

• -1

Multiple Choice

What is the charge, or oxidation number, for elements in Group 13?

• + 3

• -5

• +13

Multiple Choice

What is the charge, or oxidation number, for elements in Group 14?

• 14

• +4/-4

• -16

Multiple Choice

Ionization energy (I.E) is...

• Energy needed to destroy an atom

• the amount of energy required to remove an electron from the outer shell (PEL) of an atom

• Energy needed to split an electron
• Energy required to add an electron

Multiple Choice

What is First ionization energy (I.E) ?

• Energy needed to destroy an atom
• the amount of energy required to remove the first electron from an atom

• Energy needed to split an electron
• Energy required to add an electron

Multiple Choice

Electronegativity is...

• the ability of an atom to attract electrons

• the ability of an atom to lose electrons
• the energy required to remove an electron from a specific atom
• how easy it is to make friends. 

Multiple Select

What is an "Atomic Radius"? (Select all that apply)

• 1. ½ the distance between two adjacent nuclei

• Half the diameter of an atom

• 1. Distance between the nucleus and the electron cloud

• the diameter of an atom

Trends graphs- When you look at your graphs, what trends
do you see across periods 2&3, and down groups 1 & 17?

Trends graphs- When you look at your graphs, what trends
do you see across periods 2&3, and down groups 1 & 17?

Nuclear pull aka electron affinity
sodium vs fluorine

►

electron affinity

►

atomic radius

►

ionization energy

►

electronegativity

Why?

Why?

# PELs
increase

Increasing nuclear charge

Ionic Radius

• Do you find ionic radius on Ref Table S?

Ionic Radius

• Rule: All positive ions will be smaller than their
"parent" atoms because they formed by losing e-

• Rule: All negative ions will be larger than

their "parent" atoms because they formed
by gaining e-.

More Periodic trends…

Which Group 1 metal is the most

reactive?

• What is the trend for reactivity for the metals in

group 1?

• What is the trend for reactivity of metals/ metallic

character of elements across a period?

increases

decreases

• What is the trend for reactivity for the metals in

group 1?

• What is the trend for reactivity of metals/ metallic

character of elements across a period?

What is the most reactive

metal on the periodic table?

What is the most reactive

metal on the periodic table?

Reactivity of non-metals/

non-metallic character

decreases

increases

Reactivity of non-metals/

non-metallic character

Reactivity of non-metals/non-metallic character

► Which element is the most reactive

non-metal on the periodic table?

e-

Reactivity of non-metals/

non-metallic character

► Which element is the most reactive

non-metal on the periodic table?

► Fluorine

e-

First Ionization Energy

Can be looked up on Reference Table S

► Unit?
► KJ/mol

What is it?

What is it?

► Ionization energy is the amount of energy required to remove an electron

from the outer shell (PEL) of an atom

► The first ionization energy is the amount of energy required to remove the

first electron from an atom

What are the trends for first IE?

Look at your graph!

What are the trends for first IE?

decreases

increases

Why?

Why?

# PELs
increase

Increasing nuclear charge

Explaining the trend…

► Increasing # PELS
► valence e- are ?

Explaining the trend…

► Increasing # PELS
► valence e- are farther from

nucleus, therefore they are easier
to remove

Explaining the trend…

• Increasing nuclear charge

• electrons are....?

• Increasing nuclear charge

• electrons are more difficult to remove

Effective Nuclear Charge

The shield between the
nucleus and the
electron is the primary
influence on the
effective nuclear
charge.

Effective nuclear
charge: charge felt on
valence electrons

Zeff = Z – S

Zeff = Effective Nuclear Charge
Z = # of protons
S = Number of inner “core” electrons

You will not need to do this calculation, but it is a

VERY good guide to figuring out nuclear pull!

Electronegativity (aka Electrolove)

► The ability of an atom to attract electrons
► introduced by Linus Pauling in 1932 who defined the new atomic property

as:

► "The power of an atom in a molecule to attract electrons to itself."

► Which element on table is best at gaining

e-?

► Fluorine

► It is __________.

e-

4.0

What are the trends for electronegativity?

What are the trends for electronegativity?

decreases

increases

► Note: Noble gases do not have electronegativity values.
► Why not?