100 likes | 441 Views
Radiometric Dating. Half-life. Radioactivity. Radioactive Isotopes are unstable and emit/capture elemental particles, causing them to change over time. Parent isotope – the original radioactive element Daughter isotope – the decay product; what the parent changes into. Half Life.
E N D
Radiometric Dating Half-life
Radioactivity • Radioactive Isotopes are unstable and emit/capture elemental particles, causing them to change over time. • Parent isotope – the original radioactive element • Daughter isotope – the decay product; what the parent changes into
Half Life • The time it takes for EXACTLY HALF of the unstable, parent isotope to decay. • This decay occurs at a CONSTANT RATE. • The half life is NOT affected by: • Time • Concentration of parent isotopes • Heat/pressure • Breakage/Crushing
Decay 100% parent 50 % parent 2 half lives 1 half life 50% daughter 25% original parent 6.25% parent 75% daughter 12.5% parent 4 half-lives 93.75% daughter 87.5% daughter 3 half-lives
Decay 100 % 75% 50% % of Original Parent 25% 0% 0 1 2 3 4 5 HALF LIVES
Types of Decay Alpha Decay – an atom emits 2 protons and 2 neutrons Atomic number and mass decrease
Types of Decay Beta decay – a neutron breaks into a proton and an electron…the electron is emitted atomic # ↑, atomic mass unchanged
Types of Decay Electron capture – one electron is captured by the nucleus Atomic number increases by 1