Chemistry

• What are isotopes?


  Atoms with the same number of protons and electrons but different number of neutrons
• What is the name given for the occurrence of different isotopes?

  Isotopy
• What are chemical properties?

  The arrangement of the electrons
• What are the physical properties?

  The number of neutrons
• What is isotope abundance?

  The percentage of each isotope of an element in a sample of the element.
• How many naturally occurring isotopes does carbon have?

  3
• What are carbons 3 naturally occurring isotopes?

  Carbon 12, Carbon 13, Carbon 14
• What are the physical properties of each isotope of carbon?

  Carbon 12 has 6 neutrons, Carbon 13 has 7 neutrons Carbon 14 has 8 neutrons
• What is the most abundant isotope of carbon?

  Carbon 12
• What is the abundance percentage of all naturally occurring carbon isotopes of carbon 12?

  98.89%
• What are the three naturally occurring isotopes of hydrogen?

  Protium,deuterium, tritium
• What is the abundance percentage and most abundant of the three hydrogen isotopes?

  Protium 99.985%
• What are the 2 naturally occurring isotopes of chlorine?

  Chlorine 35 and 37
• What is the most abundant isotope of chlorine?

  Chlorine -35 at 75%
• What the percentage occurrence of chlorine-37

  25%
• What is relative atomic mass?

  The average mass of one atom of element compared to one- twelfth the mass of an atom of carbon-12
• What is the symbol for relative atomic mass?

  Ar(subscripts r )
• What is the formula to calculate relative atomic mass

  The abundance/100 x the isotope of the atom
• What is a radioactive isotope?

  A radioactive isotope has an unstable nucleus which decays spontaneously to a more stable form by emitting particles and radiation
• What is half life of and isotope?

  The time taken for half of the nuclei in a sample of a a radioactive isotope to undergo radioactive decay is known as the half- life of the isotope
• What a the main type of particles and radiation emitted by radioactive isotopes ?

  Alpha particles, beta particles, gamma particles
• Alpha particles


  2 protons

  +2 charge
• Beta particles


  1 electron

  -1 charge
• Gamma radiation


  1) a form of high energy electromagnetic radiation

  2) no mass

  3)no charge
• What are the 5 uses of radioactive isotopes?

  1) Carbon-14 dating

  2) Radiotherapy

  3) Tracers

  4) Energy generation

  5) heart pacemakers
• What is carbon 14 dating

  Carbon- 14 dating is used to determine the age of plant and animal remains up about 60 000 years old.
• Why is it possible to use carbon 14 to fine the age of remains?

  All living organisms contain carbon 14 and carbon 12 in a specific ration by mass.
• How do the determine the ages of the remains?

  Using the half life of radioactive carbon-14 which is 5700 years.
• What is radiotherapy?


  Uses of radiation to cure or control cancer
• How does the radiotherapy work?

  Irradiation can be carried out by directing a beam of gamma radiation from cobalt-60 source at the cancerous growth.
• What isotope is used in external irradiation of cancers?

  Cobalt- 60
• How would internal irradiation work

  Either injecting a radioactive isotope, usually a beta or gamma emitter, into target area, or placing a radiation source in a tiny protective capsule or wire directly at the site of the cancerous tumor.
• What is the wire that can be placed at the site of the cancerous tumor called?

  A radioactive seed
• Which isotope treats thyroid cancer?

  Iodine-131
• What isotopes are used to cure breast cancer?

  Iridium-192
• What isotopes are used to cure prostate cancer?

  Palladium-103
• What isotopes are used to cure brain tumors?

  Iodine -125
• What are tracers?


  They are used in the medical field as a diagnostic tool.
• What are the half- lives for tracers like?

  They have short- half lives and do not remain in the body very long.
• Which type of radiation is emitted from tracers?

  Gamma rays