https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:atomic-structure/v/protons-neutrons-and-electrons-in-atoms 2025-11-01T06:31:04.963641538Z 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. Wieteke Holthuijzen video https://cdn.kastatic.org/ka_thumbnails_cache/b0e49086-7776-4d8b-8b13-7afbfd62b856_1280_720_base.png 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. https://cdn.kastatic.org/ka-youtube-converted/lz_gMkQr7YE.mp4/lz_gMkQr7YE.mp4 151 What Components Contribute to the Mass of an Atom? https://www.khanacademy.org/science/mh-grade-8-science/x0f256b8de9c7cf34:inside-the-atom/x0f256b8de9c7cf34:atomic-models/e/lo-3-1-constituents-of-atom-and-their-charge 2026-04-28T12:50:36.141790462Z Constituents of atom and their charge Let's solve some problems to better understand what is inside the atom and the charge of it's constituent particles. Aakash Bagga exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:atomic-structure/e/understand-atomic-structure 2026-04-26T16:30:39.382257956Z Understand: Atomic structure Check your understanding of atomic structure in this set of free practice questions. Megan Cohn exercise