The Periodic Table: Groups, Periods, and Trends Complete Study Guide

Author: The presentation and material were prepared by Alyssa Withers.
Topic: The Periodic Table: Groups and Periods.
Slide Navigation Instructions: * READ: When the book symbol is present, students should read the slide. No writing is required. * DRAG AND DROP: When this symbol is present, students must move correct responses from an Answer Bank to the designated area. * TYPE: When this symbol is present, students must type the correct response into blank spaces.

Periods: The horizontal rows of the periodic table are called periods. There are and a total of $7$ periods.
Groups: The vertical columns of the periodic table are called groups. There are a total of $18$ groups.
Identifying Elements by Location: * Group 16, Period 5: Tellurium ( $Te$ ). * Group 2, Period 3: Magnesium ( $Mg$ ). * Group 17, Period 2: Fluorine ( $F$ ). * Group 2, Period 4: Calcium ( $Ca$ ). * Group 8, Period 4: Iron ( $Fe$ ).
Defining Group and Period for Specific Elements: * Chlorine ( $Cl$ ): Found in Group $17$ , Period $3$ . * Barium ( $Ba$ ): Found in Group $2$ , Period $6$ . * Silver ( $Ag$ ): Found in Group $11$ , Period $5$ .

Types of Elements: The table is divided into three primary categories: metals, nonmetals, and metalloids. * Metals: Located on the left and center of the table. Examples include Sodium ( $Na$ ) and Gold ( $Au$ ). * Nonmetals: Located on the right side of the table (with the exception of Hydrogen). Examples include Bromine ( $Br$ ) and Nitrogen ( $N$ ). * Metalloids: Located along the staircase boundary between metals and nonmetals. Examples include Silicon ( $Si$ ) and Germanium ( $Ge$ ).
Physical and Chemical Properties: * Metals: * Hard and shiny appearance. * Some are magnetic. * Good conductors of heat and electricity. * Characterized as malleable and ductile. * Nonmetals: * Soft and brittle in solid form. * Some exist as gases at room temperature. * Possess lower density compared to metals.

Group Characteristics: Elements within the same group share similar chemical and physical properties.
Specific Group Identifiers: * Group 1: Alkali Metals. * Group 2: Alkaline Earth Metals. * Groups 3-12: Transition Metals. * Group 17: Halogens. * Group 18: Noble Gases. * Bottom Sections: Lanthanides and Actinides are located below the main groups.
Notable Elements within Groups: * Hydrogen ( $H$ ): The only Group $1$ element that is NOT an Alkali Metal. * Lithium ( $Li$ ): The lightest Alkali Metal. * Francium ( $Fr$ ): The heaviest Alkali Metal. * Chlorine ( $Cl$ ): A member of the Halogens group. * Radium ( $Ra$ ): The Alkaline Earth Metal with the greatest mass. * Copper ( $Cu$ ): A Transition Metal found in Period $4$ . * Helium ( $He$ ): The lightest Noble Gas. * Scandium ( $Sc$ ): The lightest Transition Metal. * Bromine ( $Br$ ): The third Halogen element. * Krypton ( $Kr$ ): The fourth Noble Gas element.

Definition: Valence electrons are the electrons found in the outermost energy level of an atom.
Maximum Capacity: The maximum number of valence electrons an atom can have is eight ( $8$ ).
Determination Method: The number of valence electrons is found by counting the groups from left to right, skipping Groups $3$ through $12$ .
Examples of Valence Electron Counts: * Nitrogen ( $N$ ): $5$ * Boron ( $B$ ): $3$ * Aluminum ( $Al$ ): $3$ * Carbon ( $C$ ): $4$ * Neon ( $Ne$ ): $8$ * Potassium ( $K$ ): $1$ * Sulfur ( $S$ ): $6$ * Bromine ( $Br$ ): $7$ * Phosphorus ( $P$ ): $5$ * Calcium ( $Ca$ ): $2$

Atomic Mass Trends: Atomic mass increases moving DOWN each group and moving RIGHT across each period. * Mass Comparisons (Largest): * Between $N$ , $Li$ , and $Be$ : Nitrogen ( $N$ ). * Between $Br$ , $F$ , and $At$ : Astatine ( $At$ ). * Between $O$ , $Se$ , and $Te$ : Tellurium ( $Te$ ). * Between $Si$ , $Cl$ , and $B$ : Chlorine ( $Cl$ ). * Ordering (Least to Greatest Mass): * $N$ (Nitrogen) < $As$ (Arsenic) < $Bi$ (Bismuth). * $Ne$ (Neon) < $Ar$ (Argon) < $Rn$ (Radon). * $Ca$ (Calcium) < $Fe$ (Iron) < $Pb$ (Lead).
Atomic Radius Trends: The atomic radius is the distance from the nucleus to the valence electrons. It increases moving DOWN each group and moving LEFT across each period. * Radius Comparisons (Largest): * Between $Na$ , $Al$ , and $Mg$ : Sodium ( $Na$ ). * Between $Rb$ , $F$ , and $N$ : Rubidium ( $Rb$ ). * Between $Ca$ , $Sr$ , and $Ba$ : Barium ( $Ba$ ). * Between $Fr$ , $Be$ , and $K$ : Francium ( $Fr$ ). * Ordering (Least to Greatest Radius): * $Ar$ (Argon) < $Si$ (Silicon) < $Na$ (Sodium). * $B$ (Boron) < $Ga$ (Gallium) < $In$ (Indium). * $Ne$ (Neon) < $Br$ (Bromine) < $Cs$ (Cesium).

Ionization Energy Trends: Ionization energy is the energy required to remove an electron from an atom. It is harder to remove electrons when they are held tightly by the nucleus. It increases moving UP each group and moving RIGHT across each period. * Ionization Comparisons (Largest): * Between $Te$ , $Po$ , and $Se$ : Selenium ( $Se$ ). * Between $Sr$ , $Te$ , and $Rb$ : Tellurium ( $Te$ ). * Between $Ga$ , $Br$ , and $F$ : Fluorine ( $F$ ). * Between $Cl$ , $Ra$ , and $Ba$ : Chlorine ( $Cl$ ). * Ordering (Least to Greatest Ionization): * $Li$ (Lithium) < $N$ (Nitrogen) < $O$ (Oxygen). * $Ra$ (Radium) < $Ba$ (Barium) < $Si$ (Silicon). * $Pb$ (Lead) < $Sn$ (Tin) < $C$ (Carbon).
Electronegativity Trends: This is a measure of how strongly an atom is attracted to electrons. In chemical bonds, electrons are more attracted to atoms with higher electronegativity. It increases moving UP each group and moving RIGHT across each period. * Electronegativity Comparisons (Largest): * Between $K$ , $Fr$ , and $Li$ : Lithium ( $Li$ ). * Between $Al$ , $Cl$ , and $P$ : Chlorine ( $Cl$ ). * Between $F$ , $Sb$ , and $Br$ : Fluorine ( $F$ ). * Between $Cs$ , $Ca$ , and $N$ : Nitrogen ( $N$ ). * Ordering (Least to Greatest Electronegativity): * $Na$ (Sodium) < $Si$ (Silicon) < $Cl$ (Chlorine). * $In$ (Indium) < $Ga$ (Gallium) < $B$ (Boron). * $Na$ (Sodium) < $Si$ (Silicon) < $O$ (Oxygen).

Reactivity Principles: Reactivity is the tendency of an atom or molecule to undergo a chemical reaction. Some elements react violently with water, while others do not react at all.
Exclusion: Noble Gas elements (Group $18$ ) are generally not reactive and are excluded from reactivity trends.
Reactivity of Metals: Increases moving DOWN each group and moving LEFT across each period. * Most Reactive Metal: Francium ( $Fr$ ) or Cesium ( $Cs$ ) is often noted (Transcript notes Francium as the most reactive). * Metal Ordering (Least to Greatest Reactivity): * $Ca$ (Calcium) < $Ba$ (Barium) < $Fr$ (Francium). * $Ti$ (Titanium) < $Zn$ (Zinc) < $Fr$ (Francium).
Reactivity of Nonmetals: Increases moving UP each group and moving RIGHT across each period. * Most Reactive Nonmetal: Fluorine ( $F$ ). * Nonmetal Ordering (Least to Greatest Reactivity): * $C$ (Carbon) < $N$ (Nitrogen) < $O$ (Oxygen).
Specific Reactivity Comparisons: * Between $Ca$ , $Mg$ , and $Cs$ : Cesium ( $Cs$ ) has the greatest reactivity. * Between $Br$ , $I$ , and $F$ : Fluorine ( $F$ ) has the greatest reactivity. * Between $Ba$ , $Cu$ , and $Sr$ : Barium ( $Ba$ ) has the greatest reactivity. * Between $O$ , $C$ , and $N$ : Oxygen ( $O$ ) has the greatest reactivity.