Atomic Mass?

  • 0 votes

Can someone explain to me Atomic mass in A level terms. thanks:)

Posted Thu 4th October, 2012 @ 20:29 by Alex

2 Answers

  • 2 votes

Relative Atomic Mass or Ar is defined as the

AVERAGE MASS OF AN ATOM OF AN ELEMENT/  1/12 THE MASS OF AN ATOM OF 12-C.

This is calculated by multiplying an element's M/Z value by its abundance. This is found out using a mass spectrometer, a topic you will study shortly, so I don't want to confuse you with all the details.

I promise it will make more sense after this topic.

Atomic no. or proton no. which is denoted by the symbol (Z) is the number of protons present in the nucleus of an atom.

Answered Thu 4th October, 2012 @ 23:59 by Ibrahim
  • 1 vote

Relative Atomic Mass- (Ar)

It's the top number when looking at an element in the periodic table.

To define it: Relative Atomic Mass is the mean mass of an atom of an element compared to one twelfth of a carbon-12 atom.

As Ibrahim said you will do it in mass spectrometry as well, we have just done it :)

It will probably make more sense after you have done that

Answered Sat 13th October, 2012 @ 20:19 by Nuha