GEOL 008 Lecture Notes - Lecture 2: Mass Number, Half-Life, Uranium-238
Document Summary
Chemistry is what helped us realize the ages of rocks that we currently understand. Element defined by the number of protons. Isotope: same element, but with different number of neutrons. Certain isotopes are unstable elements have an optimal balance of protons and neutrons. Ex: 6 protons and 6 neutrons are stable, 6 protons and 7 neutrons are stable, 6 protons and 8 protons are unstable. Unstable isotopes are naturally and spontaneously decay number of protons changes (i. e. element changes) Radiation (particles and heat) is emitted during decay. Shoots out particles and production of heat is what"s dangerous to us. The time it takes to decay is different for every isotope. Ends up as stable nitrogen- 14 (7 protons, 7 neutrons) Odds of decay are 50 : 50. Half-life: the amount of time it takes for half of the parent to decay (=one round of penny flips) Every isotope has a different half-life, but follows exponential curve.
