[دلوعة حبيبها]

لو سمحتوا شلون نحول فقرهـ E

3. Which of the following samples contains the greatest number of atoms?
A. 100 g of Pb
B. 2.0 mole of Ar
C. 0.1 mole of Fe
D. 5 g of He
E. 20 million O2 molecules