Question

What is the mass in grams of `7.9xx10^21` uranium atoms?

Show work and explain please

Answer 1

Well what is the mass of `"Avogadro's Number of uranium atoms?"`

Explanation:

A quick glimpse at the Periodic Table gives the molar mass of uranium as `231.8*g*mol^-1`.

Now, by definition, this mass is equivalent to the mass of `"Avogadro's Number of uranium atoms."` And so to get the mass of the specified number, we take the product of the quotient:

`(7.9xx10^21*"uranium atoms")/(6.022xx10^23*"uranium atoms"*mol^-1)xx231.8*g*mol^-1`

And my calculator says that this represents approx. a `3*g` mass....