Answer:
Fission is the splitting of a large atom into two or more smaller ones. Fusion is the fusing of two or more lighter atoms into a larger one. Fission reaction does not normally occur in nature.
Explanation:
Quizlet
The number of hours required : 37.2 hours
<h3>Further explanation</h3>
Given
⁴²K (potassium -42)
Required
The number of hours
Solution
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
Based on Table N(attached), the half-life for ⁴²K is 12.4 hours, which means half of a sample of ⁴²K will decay in 12.4 hours
For three half-life periods :

mol CaCl₂ = 1.2 x 10²⁴ : 6.02 x 10²³ = 1.993
mass = 1.993 x 111 g/mol = 221.223 g
352.8
with this all you have to do is move the decimal point to the right 2 times.
Two Half Cell reactions are as,
Reduction: PbO₂ + 2e⁻ → Pb²⁺
As it is acidic medium reaction, so add H⁺ on reactant side as it has more number of oxygen atoms and add H₂O on product side, and balance tehe elements, So,
4 H⁺ + PbO₂ + 2e⁻ → Pb²⁺ + 2 H₂O (1)
Oxidation: I⁻ → I₂ + 1e⁻
Balance Number of elements along with electrons,
2 I⁻ → I₂ + 2e⁻ (2)
Compare eq. 1 and 2,
4 H⁺ + PbO₂ + 2e⁻ → Pb²⁺ + 2 H₂O
2 I⁻ → I₂ + 2e⁻
⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻
PbO₂ + 2 I⁻ + 4 H⁺ → Pb²⁺ + I₂ + 2H₂O
Number of Coefficients = 11