https://www.khanacademy.org/math/engageny-precalc/precalc-3/precalc-3c-exp-lop/v/half-life 2021-01-04T18:35:20Z Half-life and carbon dating Carbon dating is a real-life example of a first-order reaction. This video explains half-life in the context of radioactive decay. Sal Khan video https://cdn.kastatic.org/googleusercontent/A1D3qsWagCLFTIIalI5f9lmbc2WgRuxZeHl7C4SaFx0cdCEbZs0ZTrEKIa3N0mypb92VTDNba1yBfX-fXn8C6lg Half-life and carbon dating Carbon dating is a real-life example of a first-order reaction. This video explains half-life in the context of radioactive decay. https://cdn.kastatic.org/ka-youtube-converted/9REPnibO4IQ.mp4/9REPnibO4IQ.mp4 751 Radioactive decay and half-life https://www.khanacademy.org/science/in-in-class-12th-physics-india/nuclei/in-in-half-life-and-decay-rate/e/half-life 2026-04-07T23:17:37.123726494Z Half-life (qualitative) Let's solve some problems to better understand the meaning of the term half-life. And remove some possible misconceptions around the same. Aakash exercise https://www.khanacademy.org/science/in-in-class-12th-physics-india/nuclei/in-in-half-life-and-decay-rate/e/half-life-intermediate 2026-04-08T01:19:59.083532605Z Half life (intermediate) Let's practice some problems to understand better the formulas that help us find the half-life of a radioactive sample and other related quantities. Satra exercise https://www.khanacademy.org/science/in-in-class-12th-physics-india/nuclei/in-in-half-life-and-decay-rate/v/exponential-decay-and-semi-log-plots 2021-01-04T18:35:19Z Exponential decay and semi-log plots Using exponential decay equation to solve for relationship between k and half-life. Using semi-log plot to get graph of a straight line with slope of -k.  Jay video https://cdn.kastatic.org/googleusercontent/15ztxHMJVy5SXYovoN9ha5u-s9eH1jy9KV0T5dIWhL--Se2DKO5cnIkqFEYjacDQtWva8Ly2V_JJkKI2Z3yk8ac Exponential decay and semi-log plots Using exponential decay equation to solve for relationship between k and half-life. Using semi-log plot to get graph of a straight line with slope of -k.  https://cdn.kastatic.org/ka-youtube-converted/vnNlvnnBX0I.mp4/vnNlvnnBX0I.mp4 616 Radioactive decay and half-life https://www.khanacademy.org/science/in-in-class-12th-physics-india/nuclei/in-in-half-life-and-decay-rate/v/exponential-decay-formula-proof-can-skip-involves-calculus 2022-11-16T04:22:43.7414897Z Exponential decay formula proof (can skip, involves calculus) We can use half-lifes of radioactive substances to determine how old something is. Using your calculus skills, learn how to use the N(t)=Ne^(-kt) exponential decay equation to measure the amount of a radioactive substance we have at time T. Sal Khan video https://cdn.kastatic.org/googleusercontent/pXYmxcmQtSWbRBiLOWo8FyzAM8wQKuePUhaYiBTb9mQnHapWxVAUoxSzVeqCVv5n4pHlL2DaoW62fYfkqeeghFrz Exponential decay formula proof (can skip, involves calculus) We can use half-lifes of radioactive substances to determine how old something is. Using your calculus skills, learn how to use the N(t)=Ne^(-kt) exponential decay equation to measure the amount of a radioactive substance we have at time T. https://cdn.kastatic.org/ka-youtube-converted/H7nrVDV8ahc.mp4/H7nrVDV8ahc.mp4 742 Radioactive decay and half-life https://www.khanacademy.org/science/in-in-class-12th-physics-india/nuclei/in-in-half-life-and-decay-rate/v/more-exponential-decay-examples 2021-01-04T18:35:17Z More exponential decay examples A few more examples of exponential decay. Practice calculating k from half-life, and calculating initial mass.  Sal Khan video https://cdn.kastatic.org/googleusercontent/jWyzY9yLbRspQ-wW6NF0avSNhlB_YIjQnu-6OtyB3nK1S01_urXr7zofgJnBt3STxrLAIpKsjWSKvOg0o6xnqw9r More exponential decay examples A few more examples of exponential decay. Practice calculating k from half-life, and calculating initial mass.  https://cdn.kastatic.org/ka-youtube-converted/Hqzakjo_dYg.mp4/Hqzakjo_dYg.mp4 442 Radioactive decay and half-life https://www.khanacademy.org/science/ap-physics-2/x0e2f5a2c:modern-physics/x0e2f5a2c:nuclear-physics/v/half-life-of-radioactive-isotopes 2021-01-04T18:35:18Z Half-life plot Definition of half-life and graphing the decay of phosphorus-32. Calculating how much phosphorus-32 remains after 57.2 days.  Jay video https://cdn.kastatic.org/googleusercontent/HPQHj-3fTxXSq1B7wgA7u-e8wXGvEiC7zVPi62FvpcD_onIE1kTwxpX4Es4YQ197WIv6htItx8aiyHNpxWfhLZtb Half-life plot Definition of half-life and graphing the decay of phosphorus-32. Calculating how much phosphorus-32 remains after 57.2 days.  https://cdn.kastatic.org/ka-youtube-converted/dnYyMHSSb8M.mp4/dnYyMHSSb8M.mp4 407 Radioactive decay and half-life https://www.khanacademy.org/science/in-in-class-12th-physics-india/nuclei/in-in-half-life-and-decay-rate/e/atomic-nucleus-questions 2026-04-07T23:36:17.218592739Z Atomic nucleus questions Questions pertaining to atomic nucleus William Gilpin exercise