Nuclear Reactions Notes Nuclear Reactions Occur in the nucleus, forming new atoms. Involve changes to protons and neutrons within the nucleus. Radioactive Decay Spontaneous breakdown of a nucleus by emitting radiation. Represented by nuclear equations. Nuclear Equations Reactants: Radioactive nucleus. Products: New nucleus and radiation particle. Balanced by conserving mass numbers and atomic numbers on both sides. Alpha Decay Alpha particle: α = 2 4 H e \alpha = {}^{4}_{2}He α = 2 4 H e Example: Uranium decay 238 < e m > 92 U → 234 < / e m > 90 T h + 2 4 H e {}^{238}<em>{92}U \rightarrow {}^{234}</em>{90}Th + {}^{4}_{2}He 238 < e m > 92 U → 234 < / e m > 90 T h + 2 4 H e Smoke detectors utilize Americium-241, which decays by alpha emission, ionizing air and creating a current. Smoke disrupts the current, triggering the alarm. Beta Decay A neutron in the nucleus converts into a proton and emits an electron (beta particle). Example: Carbon-14 decay 14 < e m > 6 C → 14 < / e m > 7 N + − 1 0 e {}^{14}<em>{6}C \rightarrow {}^{14}</em>{7}N + {}^{0}_{-1}e 14 < e m > 6 C → 14 < / e m > 7 N + − 1 0 e Positron Emission A proton in the nucleus converts into a neutron, emitting a positron (positive electron). Positron: + 1 0 e {}^{0}_{+1}e + 1 0 e Example: Manganese-49 decay 49 < e m > 25 M n → 49 < / e m > 24 C r + + 1 0 e {}^{49}<em>{25}Mn \rightarrow {}^{49}</em>{24}Cr + {}^{0}_{+1}e 49 < e m > 25 M n → 49 < / e m > 24 C r + + 1 0 e Gamma Radiation Emission of energy; no change in mass number or atomic number. Does not alter the identity of the species. Synthetic Reactions Man-made reactions where a stable nucleus is bombarded with a particle. Used to create elements with atomic numbers greater than 92 (transuranic elements). Example: Bombarding Boron-10 with alpha particles to produce a radioactive nucleus. Balancing Nuclear Equations Ensure the sum of mass numbers and atomic numbers are equal on both sides of the equation. Knowt Play Call Kai