Question

Calculate the number of carbon atoms present in 0.012g of C-12?

Answer 1

`~~6.02*10^20` atoms

Explanation:

Avogadro's number is the number of atoms present in exactly `12 \ "g"` of carbon-12, that is around `6.02*10^23`

We have: `0.012\ "g" = (12 \ "g")/1000`

So, there will be a total of

`(6.02*10^23)/1000=6.02*10^20 \ "carbon atoms in" \ "0.012g of carbon-12".`

Answer 2

see a step process below;

Explanation:

Note that the carbon is `12` which is already known in the question..

But first, recall that;

`"no of moles of carbon" = ("no of entity" ("atoms"))/"avogadros constant"`

Where;

`"no of moles of carbon" = "mass"/"molar mass"`

`"avogadros constant" = 6.022 × 10^23`, representing the number of atoms..

`"no of entity" = "number of carbon atoms present"`

First, we have to know the no of moles of carbon, and to get that, we should use;

`"no of moles of carbon" = "mass"/"molar mass"`

Where;

`"mass" = 0.012g`

`"molar mass" = 12gmol^-1`

Substituting the values we should have;

`"no of moles of carbon" = (0.012cancelg)/(12cancelgmol^-1) = 0.001mol`

Now, having;

`"no of moles of carbon" = ("no of entity" ("atoms"))/"avogadros constant"`

`"no of entity" ("atoms") = "no of moles of carbon" xx "avogadros constant"`

`"no of entity" ("atoms") = 1 xx 10^-3 xx 6.022 × 10^23`

`"no of entity" ("atoms") = 6.022 × 10^(23 - 3)`

`"no of entity" ("atoms") = 6.022 × 10^20"atoms"`

Hope this helps!