https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:classifying-matter/xc370bc422b7f75fc:compounds/v/compounds-and-chemical-formulas 2025-01-16T17:32:17.772857468Z Compounds and chemical formulas Some substances, like copper or gold, are pure elements. Others, like water (H₂O), are compounds—made from two or more elements in fixed ratios, chemically bonded. Each compound has a unique formula, like CO₂ for carbon dioxide, representing its specific atomic arrangement. Compounds form molecules, tightly bonded units, creating an incredible diversity of substances in nature. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/e3e4181e-5236-462c-82b7-64099d59b95c_1280_720_base.png Compounds and chemical formulas Some substances, like copper or gold, are pure elements. Others, like water (H₂O), are compounds—made from two or more elements in fixed ratios, chemically bonded. Each compound has a unique formula, like CO₂ for carbon dioxide, representing its specific atomic arrangement. Compounds form molecules, tightly bonded units, creating an incredible diversity of substances in nature. https://cdn.kastatic.org/ka-youtube-converted/36nlbUdRvUM.mp4/36nlbUdRvUM.mp4 361 Writing chemical formulas https://www.khanacademy.org/science/strengthened-shs-chemistry-1/x174677b2bfa4bea2:measurements-in-chemistry/x174677b2bfa4bea2:writing-chemical-formulas/v/worked-example-formula-for-an-ionic-compound-ur 2025-08-08T00:24:37.843818748Z Worked example: Formula for an ionic compound Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Worked example: Formula for an ionic compound Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/NN83jv4mw8Q.mp4/NN83jv4mw8Q.mp4 211 Writing chemical formulas 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 Writing chemical formulas 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 https://www.khanacademy.org/science/strengthened-shs-chemistry-1/x174677b2bfa4bea2:measurements-in-chemistry/x174677b2bfa4bea2:writing-chemical-formulas/e/molecular-formulas 2026-03-27T06:59:58.632106018Z Identify molecular formulas Let's practice remembering molecular formulas for some common compounds. Chaitra exercise https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:structure-of-nature-and-matter/x0c8b40bd4b242f0b:elements-compounds-and-symbols-of-elements/e/compounds-and-chemical-formulas 2026-04-08T00:16:02.937952483Z Compounds and Chemical formulas Lets answer some questions! Shankar R exercise