https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:ions/v/introduction-to-ions 2023-12-18T19:15:22.874322042Z Introduction to ions An atom with an electric charge is called an ion. A positively charged ion (a cation) has more protons than electrons. A negatively charged ion (an anion) has more electrons than protons. video https://cdn.kastatic.org/googleusercontent/UAwfb6XNMO4aUhZwvvmHQIdu3oURWLZJAN_mgOX6sOKBYgq3IYFVWVOwlkBsC4Q_ry-upfT73FEpiQZ9YXvrRuHB Introduction to ions An atom with an electric charge is called an ion. A positively charged ion (a cation) has more protons than electrons. A negatively charged ion (an anion) has more electrons than protons. https://cdn.kastatic.org/ka-youtube-converted/zTUnjPALX_U.mp4/zTUnjPALX_U.mp4 397 Compound Formation https://www.khanacademy.org/science/class-9-chemistry/x46dd29ce84a663ea:structure-of-the-atom/x46dd29ce84a663ea:atomic-number-mass-number-isotopes-and-isobars/v/worked-example-identifying-isotopes-and-ions 2021-03-18T10:33:23Z Worked example: Identifying isotopes and ions Identifying isotopes and ions from the number of electrons, protons and neutrons, and vice versa.  video https://cdn.kastatic.org/googleusercontent/lifCymNe8jSpWZ8PDns689V6TAPEOUKLR6BZvEYueut1r3KwY4GrgT9UmX5v5LOUff8kLwadt3nDhbugyVQHBGw Worked example: Identifying isotopes and ions Identifying isotopes and ions from the number of electrons, protons and neutrons, and vice versa.  https://cdn.kastatic.org/ka-youtube-converted/koAFBScR41A.mp4/koAFBScR41A.mp4 225 Compound Formation https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:ions/e/understand-ions 2026-01-23T20:40:31.40044183Z Understand: ions Check your understanding of ions in this set of free practice questions. Megan Cohn exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:ions/e/apply-ions 2026-01-23T20:40:31.40044183Z Apply: ions Apply your understanding of ions in this set of free practice questions. Megan Cohn exercise https://www.khanacademy.org/science/chemistry/acids-and-bases-topic/copy-of-solubility-equilibria-mcat/v/common-polyatomic-ions 2021-02-15T02:44:57Z Common polyatomic ions Reviewing the common polyatomic ions, and explaining common suffixes and prefixes to help remember the formulas.  Jay video https://cdn.kastatic.org/googleusercontent/33vRsC7UGI-xHw8vLHVajCFPAUqsaY2J7OYNUUski1vkPTK2mXqNiHZQo8iri-3C2L9Azzs7jROQsC-5ZeCYR6I Common polyatomic ions Reviewing the common polyatomic ions, and explaining common suffixes and prefixes to help remember the formulas.  https://cdn.kastatic.org/ka-youtube-converted/DpnUrVXSLaQ.mp4/DpnUrVXSLaQ.mp4 348 Compound Formation https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atomic-models-and-periodicity/x2613d8165d88df5e:the-periodic-table/e/apply-number-of-valence-electrons 2024-06-26T17:43:47.400140177Z Apply: number of valence electrons Apply your knowledge of valence electrons for main group elements in this set of free practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:ionic-compounds/e/find-the-formula-for-ionic-compounds 2025-02-06T18:17:42.147590351Z Find the formula for ionic compounds Practice finding the formula when given the name of an ionic compound. Yuki exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-bonding/x2613d8165d88df5e:ionic-nomenclature/v/naming-ions-and-ionic-compounds 2022-10-26T22:01:10.867792203Z Naming ions and ionic compounds Ionic compounds are neutral compounds made up of positively charged ions called cations and negatively charged ions called anions. For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion. For example, KCl, an ionic compound that contains K⁺ and Cl⁻ ions, is named potassium chloride. video https://cdn.kastatic.org/googleusercontent/F9fhxeAzbl5tczOC_KxI5UnfufCJyVdO9qXgu-Rltqyf00aQlHvx_6KjnT27peERAhBSPipQTUL_5Zz001iLpgdW Naming ions and ionic compounds Ionic compounds are neutral compounds made up of positively charged ions called cations and negatively charged ions called anions. For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion. For example, KCl, an ionic compound that contains K⁺ and Cl⁻ ions, is named potassium chloride. https://cdn.kastatic.org/ka-youtube-converted/ptAw20kem90.mp4/ptAw20kem90.mp4 237 Compound Formation https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:ionic-compounds/e/naming-ionic-compounds 2026-03-29T17:54:23.483136198Z Naming ionic compounds Practice naming ionic compounds when given the formula Yuki exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-bonding/x2613d8165d88df5e:ionic-nomenclature/v/naming-ionic-compound-with-polyvalent-ion 2021-03-18T10:33:23Z Naming ionic compound with polyvalent ion Naming ionic compounds that contain polyvalent ions, using example of cobalt (III) sulfide. video https://cdn.kastatic.org/googleusercontent/sxisshpuJ9O_2ZZjQvIjFGtLso07gFMAoyk38AXaNrm0p6xisnDoq1wep1D35GeS_-3QwEcEQ-Q_Wx31ltj-MCoE Naming ionic compound with polyvalent ion Naming ionic compounds that contain polyvalent ions, using example of cobalt (III) sulfide. https://cdn.kastatic.org/ka-youtube-converted/vVTwzjvWySs.mp4/vVTwzjvWySs.mp4 242 Compound Formation https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:atomic-structure-and-properties/x2eef969c74e0d802:valence-electrons-and-ionic-compounds/v/formula-for-ionic-compounds 2021-03-18T10:33:23Z Worked example: Finding the formula of an ionic compound To find the formula of an ionic compound, first identify the cation and write down its symbol and charge. Then, identify the anion and write down its symbol and charge. Finally, combine the two ions to form an electrically neutral compound. In this video, we'll walk through this process for the ionic compound calcium bromide. Sal Khan video https://cdn.kastatic.org/googleusercontent/uFzvQna9JIfbEJWn_g8kE_QLI6lwhccLp5EDsU3uvCI7eDoPW8Ot2aHw_IqS9s7G-M4WbFPK58RpSVckceItSlSJ Worked example: Finding the formula of an ionic compound To find the formula of an ionic compound, first identify the cation and write down its symbol and charge. Then, identify the anion and write down its symbol and charge. Finally, combine the two ions to form an electrically neutral compound. In this video, we'll walk through this process for the ionic compound calcium bromide. https://cdn.kastatic.org/ka-youtube-converted/8_fMpRUsnBk.mp4/8_fMpRUsnBk.mp4 179 Compound Formation https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:ionic-compounds/v/worked-example-formula-for-an-ionic-compound 2023-06-26T12:36:08.867767149Z Worked example: Formula for an ionic compound Let's understand how to write the formula for ionic compounds! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Worked example: Formula for an ionic compound Let's understand how to write the formula for ionic compounds! https://cdn.kastatic.org/ka-youtube-converted/rjsx6MP0Vos.mp4/rjsx6MP0Vos.mp4 211 Compound Formation https://www.khanacademy.org/science/class-9-chemistry/x46dd29ce84a663ea:atoms-and-molecules/x46dd29ce84a663ea:writing-chemical-formulae/e/predicting-the-formula-of-the-given-ionic-compound 2026-03-06T09:40:40.837655949Z Predicting the formula of the given compound Let's solve a few problems to identify the correct formula of a given ionic compound. Aanchal Arora exercise