<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles.
4 mol He ( </span>6.022 x 10^23 atoms / mole ) = 2.4088 x 10^34 atoms He
Answer:

Explanation:
If the fission is induced by two neutrons, the unbalanced equation is

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation .
Balancing the superscripts, we get
2 + 239 = 89 + 149 + x
241 = 238 + x
x = 3
The balanced nuclear equation is

