Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now! https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-elements-and-the-periodic-table/x2613d8165d88df5e:atomic-structure/v/protons-neutrons-and-electrons-in-atoms

Atoms are made up of three types of subatomic particles: protons, neutrons, and electrons. Protons and neutrons are found in the nucleus, the dense region at the center of an atom. Electrons are found outside the nucleus. Protons are positively charged and have a mass of about 1 u. Neutrons are neutral (have no charge) and also have a mass of about 1 u. Electrons are negatively charged and have a much smaller mass of about 0.0005 u.

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://www.khanacademy.org/donate

Volunteer here: https://www.khanacademy.org/contribute