Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hey peeps,

    I have an assignment that I just can't figure out.
    The introduction is

    A molecule of methane, CH4, forms a regular tetrahedron
    with the four hydrogen atoms at the vertices and the carbon
    atom at the centroid. Let the vertices of the first three
    hydrogen atoms be (1, 0, 0), (0, 1, 0), and (0, 0, 1)

    I'm stuck on part D-F

    d) Determine the coordinates of the fourth hydrogen
    atom using the condition that all hydrogen atoms
    must be equidistant.
    (e) Determine the coordinates of the carbon atom by
    computing the “average” position of the four hydrogen
    atoms (i.e., add the hydrogen position vectors and
    divide by 4).
    (f) Compute the bond angle, i.e., the angle between the
    lines that join the carbon atom to two of the hydrogen
    atoms.

    If anyone has any suggestions how I can tackle any of these I'd be really grateful!!!

    Thanks!

    Edit: actually I think I found part D as (0.5,0.5,0.5)
    • Study Helper
    Offline

    13
    Study Helper
    (Original post by Scotty Bear)
    Edit: actually I think I found part D as (0.5,0.5,0.5)
    You might like to check the distances with that as your 4th set of coordinates.


    PS: Is this assessed work?
    • Thread Starter
    Offline

    0
    ReputationRep:
    No it's just our weekly homework.

    It's (1,1,1) not 0.5 right.
    • Study Helper
    Offline

    13
    Study Helper
    (Original post by Scotty Bear)
    No it's just our weekly homework.
    Cool. As we're not allowed to help with assessed work.

    It's (1,1,1) not 0.5 right.
    The three given points define a plane, and there will be two possibilities for the fourth point, such that all four are equidistant.

    (1,1,1) is one of them.
    • Study Helper
    Offline

    13
    Study Helper
    Part (e) is straight forward for you, I presume.

    For part (f), you could use the dot product, if you've covered it.
    Or, use the cosine rule, on a triangle consisting of the carbon atom, and any two of the hydrogens.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Would you rather give up salt or pepper?
    Useful resources

    Make your revision easier

    Maths

    Maths Forum posting guidelines

    Not sure where to post? Read the updated guidelines here

    Equations

    How to use LaTex

    Writing equations the easy way

    Student revising

    Study habits of A* students

    Top tips from students who have already aced their exams

    Study Planner

    Create your own Study Planner

    Never miss a deadline again

    Polling station sign

    Thinking about a maths degree?

    Chat with other maths applicants

    Can you help? Study help unanswered threads

    Groups associated with this forum:

    View associated groups
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Write a reply...
    Reply
    Hide
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.