Atomic structure

• Who proposed the idea that all matter is made up of tiny balls called "atomos"?

  Democritus
• What did John Dalton agree with Democritus about matter?

  That matter is made up of tiny different "atoms" that cannot be broken up
• What are isotopes?

  • Different forms of the same element
  • Same number of protons (same atomic number)
  • Different number of neutrons
• What is the atomic number of an element?

  The number of protons in the nucleus of an atom
• How is the mass number of an atom calculated?

  By adding the number of protons and neutrons in the nucleus
• What is an example of an isotope of oxygen?

  ¹⁸O
• What happens to unstable isotopes over time?

  They tend to decay into other elements and emit radiation
• What is radioactive decay?

  The process by which unstable isotopes emit radiation to become more stable
• What type of radiation is emitted during alpha decay?

  An alpha particle
• What is an alpha particle composed of?

  Two protons and two neutrons
• How far can alpha particles penetrate materials?

  They are stopped quickly and do not penetrate very far
• What is a beta particle?

  A fast-moving electron released by the nucleus
• What happens to a neutron during beta decay?

  It turns into a proton
• What are gamma rays?

  Waves of electromagnetic radiation released by the nucleus
• How can gamma rays be stopped?

  By thick sheets of lead or concrete
• What is ionising radiation?

  Radiation that knocks electrons off atoms, creating positive ions
• What is the effect of lower doses of radiation?

  They can cause minor damage and potentially lead to cancer
• What is an example of a radioactive isotope used in medical imaging?

  Iodine-123
• What should be considered when using radioactive materials in medicine?

  The benefits and risks of using the materials
• What is nuclear fission?

  A type of nuclear reaction that releases energy by splitting a large, unstable nucleus
• What are the risks associated with radiation exposure?

  • Tissue damage
  • Increased cancer risk
  • Symptoms from high doses: sickness, hair loss, etc.