Homework Help

The _____ of an element is the average mass of an element's naturally occuring atom, or...

user profile pic

user6607352 | eNotes Newbie

Posted February 19, 2013 at 3:21 PM via web

dislike 1 like

The _____ of an element is the average mass of an element's naturally occuring atom, or isotopes, taking into account the _____ of each isotope.

3 Answers | Add Yours

user profile pic

llltkl | College Teacher | (Level 3) Valedictorian

Posted February 19, 2013 at 5:24 PM (Answer #1)

dislike 1 like

The atomic mass of an element is the average mass of an element's naturally occurring atoms, or isotopes, taking into account the relative abundance of each isotope.

 For example, Chlorine has two principal stable isotopes, 35Cl (75.78%) and 37Cl (24.22%), found in the relative proportions of 37.89:12.11, respectively, giving chlorine a standard atomic mass of 35.453 amu. Similarly Carbon 12 has an atomic mass of 12.00 (a special case indeed) and a natural abundance of 0.9893. So nearly 99% of all carbon is carbon 12. There are two heavier isotopes too, carbon 13 and carbon 14. Carbon 13 has an atomic mass of 13.00335 and a natural abundance of 0.0107 (about 1.1%). Carbon 14 has an atomic mass of 14.003 and an abundance of 0.000000000001 (1 part in a trillion). All these contribute to make the accepted atomic mass of carbon 12.011.

Sources:

user profile pic

atyourservice | Student, Grade 10 | (Level 3) Valedictorian

Posted June 24, 2014 at 2:07 AM (Answer #2)

dislike 0 like

The atomic mass of an element is the average mass of an element's naturally occurring atoms, or isotopes, taking into account the percentage of each isotope.

user profile pic

givingiswinning | Student, Grade 10 | (Level 1) Valedictorian

Posted July 31, 2014 at 11:49 PM (Answer #3)

dislike 0 like

The atomic mass of an element is the average mass of an element's naturally occurring atoms, or isotopes, taking into account the percentage of each isotope.

 
 

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes