How do I determine the mass of one atom of an element?

1 Answer
Mar 12, 2015

Refer to the explanation.

Explanation:

In order to determine the mass of one atom of an element, you must determine its molar mass, which is its atomic weight on the periodic table in g/mol, and you need to know the relationship between moles and the number of atoms: #"1 mol of atoms"# = #6.022xx10^23# #"atoms"#. Then divide the molar mass by #6.022xx10^23# #"atoms/mol"#.

Example:
What is the mass of one copper #("Cu")# atom?

Solution:
The atomic weight of copper is #"63.456 u"#, so its molar mass is #"63.456g/mol"#.

Divide the molar mass by #6.022xx10^23# #"atoms/mol"#.

#(63.456"g"/color(red)cancel(color(black)("mol")))/(6.022xx10^23"atoms"/color(red)cancel(color(black)("mol")))=1.054xx 10^(-22)# #"g/atom"#

The mass of one Cu atom is #1.054xx10^(-22)# #"g"#.