How much lead (pb) is in 5.07 × 1012 atoms of lead? answer in units of mol?

2.49⋅10−12moles Pb

Before doing any calculations, it's worth noting that atoms do not contain moles, it's the other way around.

A mole is simply a collection of atoms. More specifically, you need to have exactly 6.022⋅1023 atoms of an element in order to have one mole of that element - this is known as Avogadro's number.

In your case, you must determine how many moles of lead would contain 1.50⋅1012atoms of lead.

Well, if you know that one mole of lead must contain 6.022⋅1023 atoms of lead, it follows that you get 1.50⋅1012 atoms of lead in

1.50⋅1012atoms of Pb⋅1 mole Pb6.022⋅1023atoms of Pb=2.49⋅10−12moles Pb

imma come back to you hold on

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.