Periodic-Table-of-Elements
Periodic Table of Elements
Title: Periodic Table of Elements by Arlene M. Cando
Learning Competencies
Key Skills to Master:
Predict chemical behavior using the periodic table (S8MT-IIIi-j-12)
Understand the historical development of the periodic table
Identify different parts of the periodic table
Write electron configurations of elements
State various uses of the periodic table across different fields
Parts of an Atom
Exercise: Identify and describe the parts of the atom based on a provided figure.
Word Unscramble
Task: Unscramble letters related to periodic table terms
TNMELEE
KALLAI EATMLS
YNGXOE
EALMT
RDOPEI
LLEMATDSOI
MOTAIC SAMS
BELON SAGSE
IOIEPRCD LEBTA
EEAVLCN NORTCEEL
Overview of the Periodic Table
Definition: An organized arrangement of elements based on their atomic mass, electron configuration, and chemical properties.
History of the Periodic Table
Importance: Condenses complex information into a manageable format for studying elements.
C.P Snow Quote:"The periodic table took jumbled details about elements and fitted them into a pattern."
Key Figures in the Development of the Periodic Table
Johann Dobereiner (1817)
The development of the periodic table could be traced back in 1817. German Chemist who Created triads of elements with similar properties, e.g., calcium, barium, strontium.
John Newlands (1863)
Proposed the Law of Octaves; elements exhibit similar properties every eight elements based on atomic mass.
Lothar Meyer and Dmitri Mendeleev (1869)
Independently arranged elements by atomic mass and grouped them by similar properties, providing a structure for periodicity.
Henry Moseley (1914)
Used X-ray frequencies to better correlate properties with atomic numbers, leading to the modern periodic law: properties are periodic functions of atomic numbers.
Modern Periodic Law
Definition: Properties of elements are periodic functions of their atomic number.
Modern Periodic Table
Elements ordered by increasing atomic number, identifying them based on the number of protons which defines the element.
Structure of the Periodic Table
Parts of the Table
Each element is box-represented; upper number indicates atomic number, lower number indicates atomic mass.
Groups and Periods
Groups or Families: Vertical columns indicating elements with similar properties.
Periods: Horizontal rows indicating increasing atomic number.
Specific Groups and Their Characteristics
Group 1: Alkali metals; highly reactive metals not found uncombined in nature.
Group 2: Alkaline earth metals; less reactive than group 1, not found uncombined.
Groups 3-12: Transition metals; generally less reactive. Two types of transition metals : Early Metals and Late Metals
Group 17: Halogens; very reactive non-metals that form salts when combined with metals.
Group 18: Noble gases; inert gases, very low reactivity.
Types of Elements
Metals
Majority of periodic table
Characteristics: shiny, good conductors, malleable, ductile. Over 85% of elements are metals.
Non-metals
Located on the right side; poor conductors, brittle, lack metallic luster.
Semi-metals (Metalloids)
Exhibit properties of both metals and non-metals; include boron, silicon, germanium, arsenic, antimony, tellurium, polonium.
Metallic Character and Reactivity
Trends:
Metallic property increases down a group and decreases across a period.
Reactivity of metals decreases across a period and increases down a group.
Electron Configuration
Definition
Arrangement of electrons within an atom, crucial for understanding chemical behavior.
Orbitals
Four types: s, p, d, f with specific shapes:
s: spherical
p: dumbbell-shaped
d: four-leaf clover shape
f: complex shapes
Electron Configuration Chart
Capacity:
s holds 2 electrons
p holds 6 electrons
d holds 10 electrons
f holds 14 electrons
Example: Chlorine (Cl)
Atomic Number: 17
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁵
Highest energy level is 3; Valence electron configuration is 3s² 3p⁵.