How do you know how many isotopes an element has without being told? I know that some elements have 5 isotopes while others could only have 3 but how do I know how many?  

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Isotopes of an element have the same number of protons, but different numbers of neutrons.  (Remember it is the number of protons that give an element its identity. ) You would not know how many isotopes an element has without being told or looking up the information.  Light elements usually have about the same number of neutrons as protons.  Heavier elements have more neutrons than protons to hold all those protons together.   Each element does not have an infinite number of isotopes.  There seem to be some combinations of protons and neutrons that make the an element more stable than other combinations.  If an isotope is unstable it is said to be radioactive.  Unstable elements will kick out particles and turn themselves into new stable elements.

Approved by eNotes Editorial Team

Posted on

Soaring plane image

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial