Question

Question #bfcbb

Answer 1

`3.8 * 10^(-21)"g"`

Explanation:

Copper has a molar mass of `"63.546 g mol"^(-1)`, which means that `1` mole of copper has a mass of `"63.546 g"`.

Now, in order to have `1` mole of copper, you need to have `6.022 * 10^(23)` atoms of copper `->` this is known as Avogadro's constant.

So, right from the start, you can say that if `1` mole of copper has a mass of `"63.546 g"` and `1` mole of copper contains `6.022 * 10^(23)` atoms of copper, then

`6.022 * 10^(23)color(white)(.)"atoms Cu " -> " 63.546 g"`

All you have to do now is to use this as a conversion factor to calculate the mass of `6` atoms of copper

`6 color(red)(cancel(color(black)("atoms Cu"))) * "63.546 g"/(6.022 * 10^(23)color(red)(cancel(color(black)("atoms Cu")))) = color(darkgreen)(ul(color(black)(3.8 * 10^(-21)color(white)(.)"g")))`

I'll leave the answer rounded to two sig figs.