Uploaded August 2025 | Updated September 2026, 2 weeks ago
Changes to an Atoms Neutrons
Dr. DeBacco
Isotopes
Isotopes are atoms of the same element that share the same atomic number (number of protons) but differ in their mass number (sum of protons and neutrons) due to varying numbers of neutrons which contribute significantly to the mass of the nucleus.
For example…
Carbon-12 (¹²C) has 6 protons and 6 neutrons and an atomic mass of exactly 12 atomic mass units
Carbon-14 (¹⁴C) has 6 protons and 8 neutrons has an atomic mass of ~14.003 amu due to two additional neutrons.
Isotopes Typically Neutral
Isotopes of an element are typically neutral (unless ionized), as the number of protons (positive charge) equals the number of electrons (negative charge) in a neutral atom.
The variation in neutrons does not affect the charge.
Types of Isotopes
Isotopes are denoted by the element’s symbol with the mass number as a superscript
Examples: ¹⁴C, ²³⁸U
Stable Isotopes: These do not undergo radioactive decay over time
Ex. ¹²C and ¹³C are stable isotopes of carbon
Radioactive (Unstable) Isotopes: These decay over time, emitting radiation
Ex. ¹⁴C is radioactive, decaying with a half-life of ~5,730 years
Radioactive isotopes are used in dating, medicine, and energy production.
Formation of Isotopes
Natural Isotopes form during stellar nucleosynthesis (in stars or supernovae), where nuclear reactions produce atoms with varying neutron counts.
Natural processes like radioactive decay can transform one isotope into another element or isotope
Example: ²³⁸U decays into ²³⁴Th
Artificial Isotopes are created in nuclear reactors or particle accelerators by bombarding atoms with neutrons or other particles, altering their neutron content
Example: Producing ⁶⁰Co for medical use
Link to Lecture Slides: drive.google.com/file/d/1La8wx3SZtyr9vz8DsYCzYIPOQ0SiZIHy/view?usp=drive_link
*Due to the description character limit the full work cited for "Changes to an Atoms Neutrons" can be viewed at... docs.google.com/document/d/1ujmkbVlK5pAJPDZQk8hrs5TMMPIuxiNh/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
Changes to an Atoms Neutrons
Dr. DeBacco
Isotopes
Isotopes are atoms of the same element that share the same atomic number (number of protons) but differ in their mass number (sum of protons and neutrons) due to varying numbers of neutrons which contribute significantly to the mass of the nucleus.
For example…
Carbon-12 (¹²C) has 6 protons and 6 neutrons and an atomic mass of exactly 12 atomic mass units
Carbon-14 (¹⁴C) has 6 protons and 8 neutrons has an atomic mass of ~14.003 amu due to two additional neutrons.
Isotopes Typically Neutral
Isotopes of an element are typically neutral (unless ionized), as the number of protons (positive charge) equals the number of electrons (negative charge) in a neutral atom.
The variation in neutrons does not affect the charge.
Types of Isotopes
Isotopes are denoted by the element’s symbol with the mass number as a superscript
Examples: ¹⁴C, ²³⁸U
Stable Isotopes: These do not undergo radioactive decay over time
Ex. ¹²C and ¹³C are stable isotopes of carbon
Radioactive (Unstable) Isotopes: These decay over time, emitting radiation
Ex. ¹⁴C is radioactive, decaying with a half-life of ~5,730 years
Radioactive isotopes are used in dating, medicine, and energy production.
Formation of Isotopes
Natural Isotopes form during stellar nucleosynthesis (in stars or supernovae), where nuclear reactions produce atoms with varying neutron counts.
Natural processes like radioactive decay can transform one isotope into another element or isotope
Example: ²³⁸U decays into ²³⁴Th
Artificial Isotopes are created in nuclear reactors or particle accelerators by bombarding atoms with neutrons or other particles, altering their neutron content
Example: Producing ⁶⁰Co for medical use
Link to Lecture Slides: drive.google.com/file/d/1La8wx3SZtyr9vz8DsYCzYIPOQ0SiZIHy/view?usp=drive_link
*Due to the description character limit the full work cited for "Changes to an Atoms Neutrons" can be viewed at... docs.google.com/document/d/1ujmkbVlK5pAJPDZQk8hrs5TMMPIuxiNh/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
