Isotopes

Isotopes

• Isotopes are atoms of an element with the same atomic number but different mass number.

• Isotopes were discovered through mass spectroscopy experiments.

• Elements were found to consist of various atoms with different masses.

• Atomic number identifies an element.

• Isotopes have the same number of protons and electrons but differ in the number of neutrons.

• Formula for mass number: no. of protons + no. of neutrons.

• Formula for the number of neutrons: mass number - number of protons.

• Atomic number equals the number of protons, which also equals the number of electrons.

Applications of Isotopes

• Common isotopes and their uses:

  • Carbon-14 for carbon dating.

  • Cobalt-60 for radiation therapy.

  • Iodine-131 for treating thyroid cancer.

  • Technetium-99 for locating brain tumors and heart cell damage.

  • Thallium-201 for detecting heart tissue damage and tumors.

  • Uranium-238 for dating sediments.

  • Uranium-235 for nuclear power.

  • Carbon-11 for monitoring organs during PET scans.

Science Connections

• Magnetic Resonance Imaging (MRI) developed by Paul Lauterber in 1971.

• MRI uses isotopes like technetium-99, iodine-131, indium-111, and gallium-67 as imaging agents.

• MRI is safer than X-ray or CT scans as it doesn't use harmful ionizing radiation.

• MRI is not suitable for patients with pacemakers or metallic implants due to magnetic field