Periodic Table Reference Notes
Chemistry
The Periodic Table • Student Reference Sheet
TEKS C.5A, C.5B, C.5C • Table Structure, Chemical Families, and Periodic Trends
Name:
Date:
Period:
1. Periodic Table Organization
TEKS C.5A
Periodic Law Moseley (1913)
Properties repeat periodically when elements are arranged by increasing atomic number (\(Z = \text{protons}\)), not atomic mass.
Groups vs. Periods
↓ GROUPS (1–18) Columns with same valence \(e^-\) and similar reactivity.
→ PERIODS (1–7) Rows with same occupied shells (\(n\)).
Metals, Metalloids & Nonmetals
Metals Left side. Shiny, conduct electricity.
Lose \(e^-\) → \(+\) ions
Metalloids Staircase (B, Si, Ge, As, Sb, Te).
Semiconductors
Nonmetals Right side. Dull, brittle insulators.
Gain \(e^-\) → \(−\) ions
Valence Electrons
Outermost \(s\) & \(p\) electrons.
Rule: Ones digit of group = val. \(e^-\) (Gr. 14 = 4 \(e^-\), Gr. 17 = 7 \(e^-\)).
O
2. Periodic Trends
TEKS C.5C
→ INCREASES: Electronegativity & Ionization Energy ← INCREASES: Atomic Radius & Metallic Reactivity ↑ Atomic Radius (Shells) ↑ IE & EN (Zeff) Transition Metals Fr F He
Atomic Radius (\(r\)) • Across: Decreases (\(\uparrow Z_{\text{eff}}\)) • Down: Increases (+ shells) Largest: Francium (Fr)
Ionization Energy Energy to remove 1 val. \(e^-\). • Across: ↑ | Down: ↓ Highest: Helium (He)
Electronegativity Pull on shared \(e^-\) in bond. • Across: ↑ | Down: ↓ Highest: F (4.0) | Grp 18 = 0
Reactivity • Metals: ↓ Down/Left • Nonmetals: ↑ Up/Right Noble Gases = Inert
3. Chemical Families
TEKS C.5B
Alkali Metals (Gr. 1) 1 val. \(e^-\)
Li, Na, K, Rb, Cs, Fr. Soft, react vigorously with \(H_2O\) to make \(H_2\) gas. Form \(+1\) cations. Stored in oil.
Alkaline Earth (Gr. 2) 2 val. \(e^-\)
Be, Mg, Ca, Sr, Ba, Ra. Denser than Group 1. Form \(+2\) cations. Found in minerals, bones, and flares.
Transition Metals (Gr. 3–12) \(d\)-block
Fe, Cu, Au, Ag. High melting points, ductile. Form variable oxidation states (\(Fe^{2+}/Fe^{3+}\)) and colored solutions.
Halogens (Gr. 17) 7 val. \(e^-\)
F, Cl, Br, I, At. Most reactive nonmetals. Diatomic (\(X_2\)). Gain 1 \(e^-\) to form \(-1\) halide ions. Salt-formers (NaCl).
Noble Gases (Gr. 18) Full Octet (8 \(e^-\))
He, Ne, Ar, Kr, Xe, Rn. Inert gases with complete outer shells (\(ns^2np^6\); He=\(1s^2\)). Electronegativity = 0.
4. Atomic Structure, Forces & Coulomb's Law
TEKS C.5C • C.6B
Coulomb’s Law \(F \propto \frac{q_1 q_2}{d^2}\)
• Charge (\(Z\)): More protons = stronger nuclear attraction.
• Distance (\(d\)): Closer electrons feel much stronger pull.
Governs all periodic trends
Nuclear Charge \(Z_{\text{eff}} = Z - S\)
Net positive pull felt by valence \(e^-\) after core shielding (\(S\)). Increases across periods as protons increase while shielding stays constant.
Pulls valence electrons inward →
Shielding Effect ↓ Down Group
Inner shell core electrons physically repel and shield valence \(e^-\). Constant across periods; increases down groups with added shells.
Weakens nuclear pull on valence \(e^-\)
Ionic Radius Ions
• Cation (\(M^+\)): Loses shell → smaller than atom.
• Anion (\(X^-\)): Added \(e^-\) repel → larger than atom.
Cation < Atom < Anion
Quick Reference Francium (Fr): Largest atom • Lowest IE • Most reactive metal | Fluorine (F): Highest EN (4.0) • Most reactive nonmetal | Helium (He): Smallest atom • Highest IE
Page 1 of 1
Periodic Table Scavenger Activity
Activity
Periodic Table Scavenger Hunt • Student Investigation
TEKS C.5A, C.5B • Use your Periodic Table Reference Sheet to locate and record answers.
Name:
Date:
Period:
Score:
Directions: Consult Reference Panels 1 & 3 to complete Parts 1 and 2 below. Write legibly on the provided lines.
Page 1 of 2
1 Part 1: Periodic Table Organization (Reference Panel 1)
TEKS C.5A
1.1 In 1869 Mendeleev arranged elements by atomic mass. In 1913 Moseley revised this. By what atomic quantity is the modern periodic table arranged?
Answer:
1.2 What structural feature do all elements in the same group share that causes them to exhibit similar chemical reactivity?
Answer:
1.3 Elements in Period 4 all share the same number of which atomic structure feature?
Answer:
1.4 Name two metalloids located along the staircase line, and state one key reason they are essential for semiconductor computer chips:
Metalloids:
Property:
2 Part 2: Chemical Families (Reference Panel 3)
TEKS C.5B
Mystery Family A Group ID
Soft, silvery metals that react violently with water releasing flammable \(H_2\) gas. Stored under mineral oil.
Family:
Valence \(e^-\):
Ion Formed:
Mystery Family B Group ID
Highly reactive nonmetals that form salts with metals. Exist as diatomic molecules (\(X_2\)) with 7 valence \(e^-\).
Family:
Valence \(e^-\):
Ion Formed:
Mystery Family C Group ID
Colorless, odorless gases that are inert and unreactive under normal conditions. Electronegativity is zero.
Family:
Valence \(e^-\):
Why Inert:
Mystery Family D Group ID
Metals in Groups 3–12. Have high melting points, show multiple oxidation states (\(Fe^{2+}/Fe^{3+}\)), and form colorful ions.
Family:
Subshell:
Feature:
Investigation 3: The Periodic Table • Scavenger Hunt Activity Turn to Page 2 for Trends & Coulomb's Law →
Activity
Periodic Trends, Coulombic Forces & Mystery Element
TEKS C.5C, C.6B • Consult Reference Panels 2 & 4 to complete Parts 3 through 5 below.
Periodic Table Scavenger Key
Teacher Key
Periodic Table Scavenger Hunt • Teacher Solutions & Rubric
TEKS C.5A, C.5B • Total: 100 Points (20 pts per Part) • Page 1: 40 Points
Grading Guide Accept scientifically equivalent phrasing
Scoring: 5 points per question item. Verify both identification and conceptual reasoning.
Page 1 of 2
1 Part 1: Periodic Table Organization (20 Points • 5 pts each)
Reference Panel 1
1.1 By what atomic quantity is the modern periodic table arranged?
Solution: Atomic Number (\(Z\)) or number of protons. (Mendeleev arranged by atomic mass).
1.2 What structural feature do all elements in the same group share?
Solution: Same number of valence electrons (outermost \(s\) and \(p\) electrons), giving similar bonding behavior.
1.3 Elements in Period 4 all share the same number of which atomic structure feature?
Solution: Same number of occupied energy shells / levels (\(n = 4\)).
1.4 Name two metalloids and state why they are essential for semiconductor computer chips:
Solution: Any two: Silicon (Si), Germanium (Ge), Boron (B), Arsenic (As), Antimony (Sb), Tellurium (Te).
Reason: They are semiconductors (conduct electricity conditionally).
2 Part 2: Chemical Families (20 Points • 5 pts each)
Reference Panel 3
Mystery Family A Solved
Soft, silvery metals reacting vigorously with water.
Family: Alkali Metals (Gr. 1)
Valence \(e^-\): 1 val. \(e^-\) (\(ns^1\))
Ion Formed: \(+1\) Cation (\(M^+\))
Mystery Family B Solved
Reactive nonmetals forming salts with metals.
Family: Halogens (Gr. 17)
Valence \(e^-\): 7 val. \(e^-\) (\(ns^2np^5\))
Ion Formed: \(-1\) Halide (\(X^-\))
Mystery Family C Solved
Colorless, odorless, inert gases with zero EN.
Family: Noble Gases (Gr. 18)
Valence \(e^-\): 8 \(e^-\) (Octet) / He=2
Why Inert: Full outer valence shell
Mystery Family D Solved
Metals with variable charges and colored solutions.
Family: Transition Metals (3–12)
Subshell: \(d\)-subshell (\(d\)-block)
Feature: Multiple oxidation states
Investigation 3: The Periodic Table • Teacher Solutions Turn to Page 2 for Trends & Mystery Element Solutions →
