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: \alpha = {}^{4}_{2}He
• Example: Uranium decay {}^{238}{92}U \rightarrow {}^{234}{90}Th + {}^{4}_{2}He
• 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}{6}C \rightarrow {}^{14}{7}N + {}^{0}_{-1}e

Positron Emission

• A proton in the nucleus converts into a neutron, emitting a positron (positive electron).
• Positron: {}^{0}_{+1}e
• Example: Manganese-49 decay {}^{49}{25}Mn \rightarrow {}^{49}{24}Cr + {}^{0}_{+1}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.