https://www.khanacademy.org/science/up-science-grade-6-revision-course-full-term/x017c12e57b64cfa8:week-1/x017c12e57b64cfa8:untitled-208/v/introduction-to-atoms-and-molecules-ur 2025-08-07T23:35:51.501752344Z Introduction to Atoms and Molecules Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Introduction to Atoms and Molecules Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/3IZtkwXC4O8.mp4/3IZtkwXC4O8.mp4 353 Elements: 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 https://www.khanacademy.org/science/grade-6-science-snc-aligned/x19bc096754f0b9af:elements-and-compounds/x19bc096754f0b9af:elements-atoms-and-molecules/e/atoms-molecules 2026-04-07T23:55:07.30621384Z Atoms & Molecules Lets answer some questions! Shankar R exercise https://www.khanacademy.org/science/ap-biology/chemistry-of-life/elements-of-life/v/elements-and-atoms 2023-03-31T23:16:47.953017837Z Elements and atoms Elements are pure substances with specific properties. Atoms are the smallest units of elements that still retain the element's properties. Atoms contain electrons, neutrons, and protons. Each element is defined by the number of protons in its nucleus. Sal Khan video https://cdn.kastatic.org/googleusercontent/zfLHeNHjPfEhSYfKtZLu6Ft_uFg2p_L9gALjUyfahbjdBzZbrDLxrg-rk_mrsUBBVIKs44ALBBI1Gv8cm2O_Ppa05g Elements and atoms Elements are pure substances with specific properties. Atoms are the smallest units of elements that still retain the element's properties. Atoms contain electrons, neutrons, and protons. Each element is defined by the number of protons in its nucleus. https://cdn.kastatic.org/ka-youtube-converted/IFKnq9QM6_A.mp4/IFKnq9QM6_A.mp4 789 Elements: atoms and molecules https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:classifying-matter/xc370bc422b7f75fc:elements-and-atoms/v/atoms 2025-01-16T17:32:17.772857468Z Atoms An atom is the smallest particle of an element that still retains all the properties of that element. Early philosophers imagined atoms as indivisible units that make up all matter, an idea revived and developed by scientists like John Dalton. Atoms are incredibly small and numerous—a single gold ring contains more atoms than stars in the universe, highlighting their fundamental role in forming the matter we see. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/6f8dc03b-b8ae-49fe-b3c7-28487059ceae_1280_720_base.png Atoms An atom is the smallest particle of an element that still retains all the properties of that element. Early philosophers imagined atoms as indivisible units that make up all matter, an idea revived and developed by scientists like John Dalton. Atoms are incredibly small and numerous—a single gold ring contains more atoms than stars in the universe, highlighting their fundamental role in forming the matter we see. https://cdn.kastatic.org/ka-youtube-converted/KyBgxe-rU48.mp4/KyBgxe-rU48.mp4 248 Elements: atoms and molecules https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:structure-of-an-atom/e/structure-of-an-atom 2023-08-13T07:34:46.711956309Z Structure of an atom Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/class-9-chemistry/x46dd29ce84a663ea:atoms-and-molecules/x46dd29ce84a663ea:what-is-an-atom/e/understand-elements-and-atoms 2026-04-20T04:40:44.098027975Z Understand: elements and atoms Check your understanding of elements and atoms in this set of free, standards-aligned practice questions. Allen Ruch exercise 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 Elements: atoms and molecules https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:atomic-structure/e/understand-atomic-structure 2026-04-07T22:59:30.107127435Z Understand: atomic structure Check your understanding of atomic structure in this set of free practice questions. Megan Cohn exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:atomic-structure/v/elements-and-atomic-number 2025-12-03T14:30:51.007256483Z Elements and atomic number Atoms come in a variety of types, called elements, each with a unique set of physical and chemical properties. An element is defined by the number of protons in its atoms, known as its atomic number. The periodic table organizes the elements by atomic number and provides other key information about them such as their names and chemical symbols. Wieteke Holthuijzen video https://cdn.kastatic.org/ka_thumbnails_cache/f9b78e3a-4de0-46ed-a0cb-3e36d84fa21b_1280_720_base.png Elements and atomic number Atoms come in a variety of types, called elements, each with a unique set of physical and chemical properties. An element is defined by the number of protons in its atoms, known as its atomic number. The periodic table organizes the elements by atomic number and provides other key information about them such as their names and chemical symbols. https://cdn.kastatic.org/ka-youtube-converted/OQi8FwPSu5o.mp4/OQi8FwPSu5o.mp4 274 Elements: atoms and molecules https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:classifying-matter/xc370bc422b7f75fc:elements-and-atoms/v/elements 2025-01-16T17:32:17.772857468Z Elements Elements are the fundamental building blocks of all matter, just as letters form the basis of all writing. With only about 100 natural elements, nature constructs everything around us—from tiny microbes to vast oceans and stars. These elements, represented by symbols on the periodic table, combine in countless ways to create the diverse materials that make up the universe. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/7bad28ff-1c16-4904-860d-48ebd21ceb41_1280_720_base.png Elements Elements are the fundamental building blocks of all matter, just as letters form the basis of all writing. With only about 100 natural elements, nature constructs everything around us—from tiny microbes to vast oceans and stars. These elements, represented by symbols on the periodic table, combine in countless ways to create the diverse materials that make up the universe. https://cdn.kastatic.org/ka-youtube-converted/PeNjuIQFd9U.mp4/PeNjuIQFd9U.mp4 313 Elements: atoms and molecules https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:structure-of-nature-and-matter/x0c8b40bd4b242f0b:elements-compounds-and-symbols-of-elements/e/symbols-and-molecular-formula-of-elements 2026-04-08T00:36:09.500768563Z Symbols and Chemical formula of elements and compounds Let's identify symbols and write molecular formula of elements Vibhor Pandey exercise https://www.khanacademy.org/science/ap-biology/chemistry-of-life/elements-of-life/a/matter-elements-atoms-article 2021-04-29T08:02:50Z Matter, elements, and atoms Learn about the structure of the atom, and how atoms make up matter. An atom is the smallest unit of matter that retains all of the chemical properties of an element.  article https://www.khanacademy.org/science/class-9-chemistry/x46dd29ce84a663ea:structure-of-the-atom/x46dd29ce84a663ea:models-of-an-atom/e/atomic-structure 2026-04-03T18:30:01.793877038Z Atomic structure Test your knowledge of atomic structure! Ashley exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:atomic-structure/e/apply-atomic-structure 2026-01-16T21:30:45.892595405Z Apply: atomic structure Apply your understanding of atomic structure in this set of free practice questions. Megan Cohn exercise https://www.khanacademy.org/science/grade-6-science-snc-aligned/x19bc096754f0b9af:elements-and-compounds/x19bc096754f0b9af:elements-atoms-and-molecules/v/covalent-bond-molecules-with-same-atoms-ur 2025-08-07T23:35:51.501752344Z Covalent bond: Molecules with same atoms Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Covalent bond: Molecules with same atoms Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/U-ShBJ_T6C4.mp4/U-ShBJ_T6C4.mp4 289 Elements: atoms and molecules https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:chemical-bonding/x426c9d2c554669cb:basics-of-covalent-bonding/e/covalent-bonding-molecules-with-same-atoms 2026-04-08T00:36:09.500768563Z Covalent bonding: Molecules with same atoms Let's solve some questions! vibhor exercise