Moles of lead(Pb) = 1.6x10^23/6.02x10^23 = 0.265 moles.
Weight of lead = moles x atomic weight of lead
= 0.265x207.2
= 54.908 grams.
Hope this helps!
It would be 1 or 2 because if the number is higher than 5 you need to round up , if its lower than 5 you need to round down.
To answer the question above, substitute the given values to the given equation,
Q(t) = Q x e^-kt
12 grams = (36 grams) x e^(-0.00011)(t)
Solving for t gives t = 9,987.38 years or approximately equal to 9,990 years. Thus, the answer is letter C.
The particles cannot move around at all. The particles are, however, still in motion.