9 Nuclear StabilityFor smaller atoms a ratio of 1:1 neutrons to protons helps to maintain stabilityC-12, N-14, O-16For larger atoms, more neutrons than protons are required to maintain stabilityPb-207, Au-198, Ta-181
11 Radioactive DecayRadioisotopes will undergo decay reactions to become more stableAlpha DecayBeta DecayPositron Emission
12 Nuclear ReactionsUnstable isotopes of one element are transformed into stable isotopes of a different element.They are not affected by outside factors, like temp and pressure. They can not be sped up or slowed down.
13 General Reaction Format ReactantsProductsStarting MaterialEnding MaterialScience equivalent of Math’s =
14 Reaction Format In Math class you might say: A – B = CIn Science, we don’t use subtractionA B + CA breaks into B and C
15 Decay ReactionsDecay reactions involve one unstable nuclei decaying (breaking down) into 2 (or more) smaller nuclei.Alpha Decay - one of the products is an alpha particleBeta Decay - one of the products is a beta particle
16 Nuclear Reactions Reactions must always Balance Mass Numbers have to balanceAtomic Numbers have to balance238 =92 =
69 Stability Elements 1-26 are made in the core of stars Elements 27-92, excluding 43 and 61, are made during a Supernova explosionNo element larger than 83 has a stable isotopeNo element larger than 92 is made in nature