Question

why are familiar objects such as pens and paper clips not commonly counted in moles?

Answer 1

The number is far to big. A single mole of jelly beans would take up the whole planet earth. So imagine the numbers we would have to go into!

Answer 2

One mole is equal to avagadro number

Avagadro's number = 6.023 X 10^23

So it is a big big number. For pens or paper clips we do not need such big unit to express any figure.

Hence we cannot count the normal pens or pencils type macro objects in terms of moles

The mole is used for atomic level particles where in a small amount such large number of identities are present