flask Periodic Table & Periodicity
The periodic table organizes all known elements so that patterns jump out: reactivity, size, and bonding behavior all follow trends you can read straight off the table. Learn to use it as a predictive tool, not just a poster.
What you will learn
- Navigate groups and periods
- Classify metals, nonmetals, and metalloids
- Predict periodic trends
- Explain valence electrons and reactivity
- Use the table to predict ion charges
High School concepts
Atomic Radius Trend Explained
Why atomic radius decreases across a period and increases down a group — shielding, effective nuclear charge, and shell additions.
Electronegativity Trend and Bond Polarity
Electronegativity: what it measures, its trend across the table, the Pauling scale, and how it predicts bond polarity.
Element Families of the Periodic Table
The named element families — alkali metals, alkaline earths, halogens, noble gases, and more — and the chemistry each family shares.
Groups and Periods: Reading the Table
Reading the periodic table's rows and columns: what periods, groups, and numbering systems tell you about each element.
Ionic Radius and Crystal Packing
How ion sizes compare to parent atoms, isoelectronic series, and using radius ratios to predict crystal coordination.
Ionization Energy Trend Explained
Why ionization energy rises across a period and falls down a group — and what successive ionization energies reveal about electron shells.
Metals, Nonmetals, and Metalloids
The staircase dividing metals, nonmetals, and metalloids: their properties, locations, and how character changes across the table.
Valence Electrons and Effective Nuclear Charge
Valence electrons: how to count them, why they control bonding, and how effective nuclear charge shapes their behavior.