Anatomy of the Periodic Table Chem-To-Go Lesson 10 Unit 3 You might want to have a periodic table handy during the video!

Quick History Henry Moseley Dmitri Mendeleev “Father of the Periodic Table” Henry Moseley Arranged the elements in order of increasing atomic mass Arranged the elements in order of increasing atomic number

Periodic Law Periodic Law - The periodic law states that certain chemical and physical properties repeat themselves every eight elements when the elements are arranged in order of increasing atomic number. Periods = rows Columns = groups

Major Classifications Metals Nonmetals Metalloids

Properties Metals Nonmetals Diverse in room temperature state of matter Non-conductors Brittle Non-lustrous Gain electrons to become stable Typically solid at room temperature Conduct electricity and heat Shiny Malleable Ductile Lose electrons to be stable

Six Important groups

Two important patterns Number of Valence Electrons = Column Number

Two important patterns Common Charge of the Ion Pattern

Atomic Radius & ionic radius Chem-To-Go Lesson 11 Unit 3

trends Trend = a repeating pattern Periodic Trend = a repeating pattern on the periodic table

Atomic radius Definition: ½ the distance between the nuclei of two identical touching atoms

Atomic radius Period trend: [row pattern]; atomic radius DECREASES from left to right across a row PERIOD TREND Group trend: [column pattern]; atomic radius DECREASES from bottom to top of a column GROUP TREND WHY? Radius decreases across a period because the nucleus is gaining more protons to become larger and more strongly positive. The electron cloud is drawn in by forces of attraction. Radius decreases up a group because there are fewer energy levels at the top of the periodic table.

SAMPLE MULTIPLE CHOICE: Atomic radius Memory Tool Use a periodic table! Find all of the elements. Apply the trend. SAMPLE MULTIPLE CHOICE: Which of the following atoms will has the smallest radius? a. Tin b. Strontium c. Selenium d. Arsenic

SAMPLE MULTIPLE CHOICE: Atomic radius Memory Tool Use a periodic table! Find all of the elements. Apply the trend. SAMPLE MULTIPLE CHOICE: 2. Which of the following atoms will has a larger radius than calcium? Aluminum b. Copper c. Potassium d. None

Ions Cation= Positively charged ion (neutral atom has lost one or more electrons) Anion= Negatively charged ion (neutral atom has gained one or more electrons)

ionic radius Definition: size of the ion; usually compared to the size of its neutral atom

ionic radius CATION RADIUS ANION RADIUS Cations form by losing electrons. As electrons are lost, the ion becomes smaller. Anions form by gaining electrons. As electrons are gained, the ion becomes larger.

Ionization Energy & Electronegativity Chem-To-Go Lesson 12 Unit 3

1st Ionization Energy Definition: the energy required to remove a first electron from an atom

1st Ionization Energy

1st Ionization energy WHY? Period trend: [row pattern]; ionization energy INCREASES from left to right across a row PERIOD TREND Group trend: [column pattern]; ionization energy INCREASES from bottom to top of a column GROUP TREND WHY? The energy needed to remove an electron increases as the nucleus becomes more strongly positive and the electrons are drawn in closer to it. The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

SHIELDING EFFECT OF CORE ELECTRONS 1st Ionization energy SHIELDING EFFECT OF CORE ELECTRONS The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

SAMPLE MULTIPLE CHOICE: 1ST Ionization Energy Memory Tool Use a periodic table! Find all of the elements. Apply the trend. SAMPLE MULTIPLE CHOICE: Which of the following atoms will has the smallest ionization energy? a. Tin b. Strontium c. Selenium d. Arsenic

SAMPLE MULTIPLE CHOICE: 1st Ionization Energy Memory Tool Use a periodic table! Find all of the elements. Apply the trend. SAMPLE MULTIPLE CHOICE: 2. Which of the following atoms has a larger ionization energy than calcium? Aluminum b. Copper c. Potassium d. None

Electronegativity Definition: the ability of an atom in a chemical bond to draw the bonding electrons closer to itself

Electronegativity Notice that the noble gases are NOT in the image. Since they don’t form bonds, they have no electronegativity values.

Electronegativity WHY? Period trend: [row pattern]; electronegativity INCREASES from left to right across a row PERIOD TREND Group trend: [column pattern]; electronegativity INCREASES from bottom to top of a column GROUP TREND WHY? The larger and more positive nuclei on the right side of the table are more likely to attract the bonding electrons An unshielded nucleus is better at attracting bonding electrons. Fewer energy levels means more electronegativity.

SAMPLE MULTIPLE CHOICE: Electronegativity Memory Tool Use a periodic table! Find all of the elements. Apply the trend. SAMPLE MULTIPLE CHOICE: Which of the following atoms will has the highest electronegativity? a. Tin b. Chlorine c. Neon d. Arsenic

SAMPLE MULTIPLE CHOICE: Electronegativity Memory Tool Use a periodic table! Find all of the elements. Apply the trend. SAMPLE MULTIPLE CHOICE: 2. Which of the following atoms will has a higher electronegativity than P? Oxygen b. Fluorine c. Helium d. None

Electron Affinity Definition: the amount of energy released when an electron is added to a neutral atom or molecule to form a negative ion. Period trend: [row pattern]; electron affinity INCREASES from left to right across a row PERIOD TREND Group trend: [column pattern]; electron affinity INCREASES from bottom to top of a column

Electron Affinity Memory Tool