Nitrogen molecule is diatomic, whereas other elements form tetraatomic molecules.
Answer is B. gas formation
Zinc is a metal. At STP, it exists as solid and is stable as it is. It is an important mineral and is used in many applications like in food, metal and drugs. Zinc can be found in the Earth's crust and also it is present in small amounts in some food.
Zinc because the only metals that would be able to reduce copper ions in solution would be hydrogen, lead, tin, nickel, iron, zinc, aluminum, Magnesium, sodium, calcium, potassium, and lithium. and according to your answer choices Zinc is the answer.