The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

Across a period from left to right, the covalent radius decreases. As you move from left to right across the periodic table, atoms have more electrons in their outer energy level and more protons ...

Lesson Plans: The Periodic Table and Bonding Download inquiry-based lesson plans and activity sheets ... Guidelines and Recommendations for Teaching Middle & High School Chemistry Learn to navigate ...