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 Atoms and Molecules https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:measurement-of-matter/x345505a97fc4a662:atoms-and-molecules/v/atomic-mass-molecular-mass-in 2025-08-14T07:14:15.492085113Z Atomic Mass & Molecular Mass What exactly is atomic mass, and how is it different from molecular or formula mass? In this video, we unravel the concept of mass in chemistry, starting with why carbon-12 is chosen as the standard, what amu (atomic mass unit) really means, and how percentage abundance plays a crucial role in calculating average atomic mass. Nitika Duggal video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Atomic Mass & Molecular Mass What exactly is atomic mass, and how is it different from molecular or formula mass? In this video, we unravel the concept of mass in chemistry, starting with why carbon-12 is chosen as the standard, what amu (atomic mass unit) really means, and how percentage abundance plays a crucial role in calculating average atomic mass. https://cdn.kastatic.org/ka-youtube-converted/MGOOiymtWjk.mp4/MGOOiymtWjk.mp4 431 Atoms and Molecules https://www.khanacademy.org/science/class-9-chemistry/x46dd29ce84a663ea:atoms-and-molecules/x46dd29ce84a663ea:molecules-and-ions/e/atoms-and-molecules 2026-04-07T23:36:17.218592739Z Atoms and molecules LO: Let's understand the concept of atoms and molecules with examples. Revathi exercise