Atomic Structure and Radioactivity Quiz

Atomic Structure and Radioactivity

• Atoms consist of electrons, protons, and neutrons
• Protons and neutrons reside in the nucleus at the atom's center
• Electrons orbit the nucleus in specific shells
• Electron shells have different energy levels
• The shell number (n) increases with energy
• Atomic radius is approximately 10-10 m
• Electrons have a negative charge (-1.6 × 10-19 C) and a mass of approximately 9.1 × 10-31 kg
• Protons have a positive charge (+1.6 × 10-19 C) and a mass of nearly 1.67 × 10-27 kg
• Neutrons are neutral and have a mass nearly equal to that of a proton (1.67 × 10-27 kg)
• Maximum number of electrons in a shell is 2n² (where n is the shell number)

Isotopes

• Isotopes are atoms of the same element with the same atomic number (Z) but different mass numbers (A)
• Isotopes have the same number of protons but different numbers of neutrons
• Isotopes have identical chemical properties
• Some isotopes are stable, while others are radioactive

Radioactivity

• Radioactivity is the spontaneous disintegration of unstable atomic nuclei (emitting α, β, and γ radiation)
• Alpha particles (α) are positively charged helium nuclei (2 protons and 2 neutrons)
• Beta particles (β) are high-speed electrons or positrons
• Gamma rays (γ) are high-energy electromagnetic radiation
• Radioisotopes have the same chemical properties as stable isotopes, but are radioactive