The periodic table | Chemistry | Khan Academy

Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! The periodic table organizes elements by atomic number, revealing patterns in their physical and chemical properties. Elements are categorized as metals, nonmetals, or metalloids based on distinct behaviors. Vertical groups share similar chemical properties based on their number of valence electrons. The octet rule explains how atoms achieve stability by gaining, losing, or sharing electrons. ------------------ Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help! Donate or volunteer today! Donate here: https://donate.khanacademy.org/give/419869/#!/donation/checkout Volunteer here: https://www.khanacademy.org/contribute?utm_source=youtube&utm_medium=desc