Answer:
1.54×10^20 atoms
Step-by-step explanation:
It's done by using the relation
N=n×L where,
N = number of entities present
n= amount of substance (mole)
L= Avogadro's constant which is 6.02×10^23
now from the question, given
n=0.000256
And L=6.02×10^23
N= 0.000256×6.02×10^23
N= 1.54×10^20 atoms