1. Decreases by 4. (B)
2. The atomic number changes. (B)
3. 56/26 Fe. (C)
4. Potassium-40;t1/2=25 days. (B)
5. Takes place in the upper atmosphere. (A)
Using the length given '12 m', because the shape of the object is a square all sides are congruent.
Basically 12+12+12+12=48 or 12 x 4= 48
The answer is 48 m
