March 28, 2024, 08:02:28 PM
Forum Rules: Read This Before Posting


Topic: Calculating Atomic Mass(Homework please help)  (Read 26570 times)

0 Members and 1 Guest are viewing this topic.

Offline pinkdiamondgail

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Calculating Atomic Mass(Homework please help)
« on: February 10, 2009, 02:19:05 PM »
 ???

Can somebody help me please I think I have the problem right but I am not sure I just need to see if I have these two problems right??

Calculate the atomic mass of bromine. the two isotopes of bromine have atomic masses and relative abundance of 78.92 amu(50.69%) and 80.92 amu (49.31%)





The element copper has natural occuriing istopes with mass numbers of 63 and 65. The relative abundance and atomic  masses are 69.2% for mass=62.93amu, and 30.8% for mass=64.93amu. Calculate the average atomic mass of copper.

Offline fyodor.pav

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
Re: Calculating Atomic Mass(Homework please help)
« Reply #1 on: February 10, 2009, 02:30:14 PM »
I'm by no means an expert, but I'm 99% sure that you just multiply the AMUs by their respective abundances and add, so...

78.92 amu * .5069 + 80.92 amu * .4931 = 79.91 amu

Offline Ak

  • Regular Member
  • ***
  • Posts: 95
  • Mole Snacks: +8/-3
  • Gender: Male
  • "Man I am so juzzed" - Bart Simpson
Re: Calculating Atomic Mass(Homework please help)
« Reply #2 on: February 10, 2009, 11:13:44 PM »
yeah thats right

Offline pinkdiamondgail

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Calculating Atomic Mass(Homework please help)
« Reply #3 on: February 10, 2009, 11:18:58 PM »
Thanks guys that's what I had I just wanted to be sure  ;D

Sponsored Links