1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: WTA : does atomic mass matter to atom's radius?

  1. May 31, 2015 #1
    1. The problem statement, all variables and given/known data
    so my friend asked this question: "what's the atomic radius ratio between He-3 and He-4?"
    2. Relevant equations

    all i know is this equation : r =nh/mv
    3. The attempt at a solution

    i thought the ratio will be same because both He-3 and He-4 have only two electrons. Correct me if im wrong please
  2. jcsd
  3. May 31, 2015 #2
    Nuclear radius will be different but atomic radius will remain the same. As atomic radius is the distance between the center of the nuclei to the outermost electron-which is same for both.

    ratio is 1 and 'not same'
  4. May 31, 2015 #3
    so to make clear things the ratio of atomic radius is same but the nuclear radius isnt same right?
  5. May 31, 2015 #4
    You should actually say atomic radius of both are same and ratio is 1.
    yes. You can understand it by the formula:


    where A-Mass number, R_0 is a constant
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted