Given that the atomic radius of silver is #145*"pm"#, how many silver atoms will span a length of #4.70*mm#?

1 Answer
Sep 6, 2017

Answer:

In effect they are asking how many lengths of #290*"pm"# will fit into a length of #4.70*mm#....

Explanation:

Now we can do this dimensionally......

#(4.70xx10^-3*m)/(290xx10^-12*m)=1.621xx10^7# individual silver atoms.....

Why did I double the given radius? Did I make an error?

We note that #1*mm-=1xx10^-3*m#...

And that #1*"picometre"-=1xx10^-12*m#

The rest is arithmetic. Of course, we have to do the ratio properly. I have never found it straightforward.