1. Chapter 6 Periodic Trends
Trends video:

2. Organizing Elements
Chemists used the properties of elements to sort them into groups.
Mendeleev arranged the elements in his period table in order of increasing mass.
In the modern periodic table, elements are arranged in order of increasing atomic mass.
Periodic law stated that when the elements are arranged in order of increasing atomic number, there is a periodic separation of their physical and chemical properties.

3. Organizing Elements Recall
Groups (Families) are the columns
Periods are the row
Representative elements are in groups 1A through 7A (1,2 and 13-17). They display a wide range of physical and chemical properties.
the s and p sublevels of representative elements are not filled.

4. Organizing Elements Representative elements include
Alkali Metals in group 1 or 1a
Alkaline Earth in Metals group 2 or 2a
Carbon Family in group 14 or 4a
Nitrogen Family in group 15 or 5a
Oxygen Family in group 16 or 6a
Halogens in group 17 or 7a

5. Organizing Elements Other Families/Groups
Transition Metals in groups 3-12 or 3b to 2b
These elements are characterized by d orbital’s that contain electrons.
Noble Gases in group 18 or 8a
Have full p orbitals
Lanthanide Series top row in F block
Actinide Series bottom row in F block
Inner transition metals include the Lanthanide and Actinide Series (bottom two rows pulled out of periodic table)
These elements are characterized by f orbital’s that contain electrons.

6. Classes of Elements
Three classes of elements are metals, nonmetals, and metalloids.
Metals are good conductors of heat and electric current
Are found on the left side of the periodic table
Metals are solid at room temperature (except mercury).
Metals are ductile (can be drawn into wires) and Malleable (hammered in to sheets)
Nonmetals are poor conductors of heat and electric current.
Are found on the right side of the periodic table
Solid nonmetals tend to be brittle.
Most are gasses at room temperature
Metalloids (or semi metals) have properties similar to metals and non metals.
Sit on the dark line (red on ours)

8. Periodic Trends
Metallic Nature: as you move across a period (left to right) the elements get less metallic; as you move down a group the elements get more metallic. Francium is most metallic element.
Metallic Nature DECREASES
Metallic Nature INCREASES

9. Metallic Nature Practice
List the elements in order of INCREASING metallic nature: As F Fr Hf Pd
Which element is the least metallic? Ca Ga Ge Kr
List the elements in order of DECREASING metallic nature: Fr Hg I Nd Pb Xe
According to metallic trends what is the least metallic element on the periodic table.

10. Metallic Nature Practice Answers
List the elements in order of INCREASING metallic nature: As F Fr Hf Pd F<As<Pd<Hf<Fr
Which element is the least metallic? Ca Ga Ge Kr Krypton (Kr)
List the elements in order of DECREASING metallic nature: Fr Hg I Nd Pt Xe Fr> Nb>Pt >Hg>I>Xe
According to metallic trends what is the least metallic element on the periodic table. Helium

11. Periodic Trends Atomic Charge the charge in the nucleus of the atom
Atomic mass the mass of the element
Both generally increase as you move across a period and down a family
Atomic Charge and mass INCREASES
Atomic Charge and mas INCREASES

12. Periodic Trends
Atomic radius is one half of the distance between the nuclei of two atoms of the same elements when the atoms are joined.
In general, atomic size increases from top to bottom within a group because you are adding energy levels (shielding effect is greater)
and decreases from left to right across a period because of effective nuclear charge (greater pull on electrons due to addition of proton)
Atomic Radius INCREASES
Atomic Radius DECREASES

13. What is effective nuclear charge and shielding effect?
The effective nuclear charge is the net positive charge experienced by an electron in a multi-electron atom.
The term "effective" is used because the shielding effect of negatively charged electrons prevents higher orbital electrons from experiencing the full nuclear charge by the repelling effect of inner-layer electrons.
The shielding effect describes the decrease in attraction between an electron and the nucleus in any atom with more than one electron shell.
when more electrons are involved, each electron feels not only the electromagnetic attraction from the positive nucleus, but also repulsion forces from other electrons in other shells. This causes the net force on electrons in outer shells to be significantly smaller in magnitude. Because of this these electrons are not as strongly bonded to the nucleus as electrons closer to the nucleus

14. Atomic Mass, Radius and Charge Practice
Arrange in order of increasing atomic Radius: I In Mo Pd Sr Te
Arrange in order of decreasing atomic mass: I In Mo Pd Sr Te
Arrange in order of increasing atomic mass: Ac Ca Lr Pa Te Th
What element has the smallest atomic radius?
What element has the smallest atomic mass?

15. Atomic Mass, Radius and Charge Practice Answers
Arrange in order of increasing atomic Radius: I In Mo Pd Sr Te I<Te<In<Pd<Mo<Sr
Arrange in order of decreasing atomic mass: I In Mo Pd Sr Te I>Te>In>Pd>Mo>Sr
Arrange in order of increasing atomic mass: Ac Ca Lr Pa Te Th Ca<Te<Ac<Pa<Th<Lr
What element has the smallest atomic radius? Helium
What element has the smallest atomic mass? Hydrogen

16. Periodic Trends
Ions is an atom or groups of atoms that has a positive or negative charge.
Positive and negative ions from when electrons are transferred between atoms.
Cation is an atom or groups of atoms with a positive charge that have lost electrons.
Metals form Cations
Anion is an atom or groups of atoms with a negative charge that have gained electrons.
Nonmetals form Anions

17. Group 1a forms +1 ion
Group 2a forms +2 ion
Group 3a forms +3 ion
Group 4a can form +4 or -4
Group 5a forms -3 ion
Group 6a forms -2 ion
Group 7a forms -1 ion
Group 8 a will not react or form ions

18. Ion Practice
Write the ion that each of the following elements will form: Al K Br Mg Cs P Ca Rn Cl S Ga Se

19. Ion Practice Answers
Write the ion that each of the following elements will form:
Al+3
K-1
Br-1
Mg+2
Cs+1
P-3
Ca+2
Rn (no ion forms)
Cl-1
S-2
Ga+3
Se-2

20. Periodic Trends
Elements form Ions to achieve a noble gas electron configuration (a full outer shell)
Full outer energy shells for MOST atoms contain 8 valance electrons.
As metals lose electrons they form a positive charge (cation) and their radius shrinks
The greater the charge the smaller the radius
As nonmetals gain electrons they form a negative charge (anion) and their radius expands
The greater the charge the larger the radius

21. Periodic Trends
Ionic radius the radius of an atom that has formed an ion by losing or gaining electrons
In general, ionic radius increases from top to bottom within a group because you are adding energy levels
and decreases from left to right across a period because of the removal/addition of electrons
Atomic Radius INCREASES
Atomic Radius DECREASES

22. Ionic & Atomic Radius practice
Use grater than (>) or less than (<) to show how the size of the atoms and ions are related.
Na Na+1
Br Ca+2
Al Al+3
S S-2
Al Na+1
Al P-3
Arrange in order of increasing Ionic size I Mg Na Rb Sr Sb

23. Periodic Trends
Ionization energy is the energy required to remove the first electron from an atom
First ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period.
Ionization Energy DECREASES
Ionization Energy INCREASES

24. Periodic Trends
Electronegativity is the ability of an atom of an element to attract electrons when the atom is in a compound.
Electronegativity values decrease from top to bottom within a group, and values tend to increase from left to right across a period.
MOST electronegativite element is Fluorine
Electronegativity DECREASES
Electronegativity INCREASES

25. Electronegativity & Ionization Energy Practice
What is most Electronegative element?
What is element with highest Ionization energy?
Put in order of decreasing ionization energy: Cs Fr K Li Na Rb
Put in order of increasing electronegativity: Al Cl Mg S P
Put in order of decreasing ionization energy: Ag I In Mo Rb Y

26. Electronegativity & Ionization Energy Practice Answers
What is most Electronegative element? Fluorine
What is element with highest Ionization energy? Helium
Put in order of decreasing ionization energy: Cs Fr K Li Na Rb Li> Na> K> Rb> Cs> Fr
Put in order of increasing electronegativity: Al Cl Mg S P Mg< Al< P< S< Cl
Put in order of decreasing ionization energy: Ag I In Mo Rb Y I> In> Mo> Y>Rb