It mostly because they're so reactive and if they were in their pure form and touched water they would have a very violent reaction. They also want to be more stable so they look for more electrons and quickly bond.
A) Calcium Dihydrogen Phosphate
B) Iron(II) Sulfate
C) Calcium Carbonate
D) Magnesium Oxide
E) Sodium Nitrite
F) Potassium iodide
At the point when a response achieves a condition of concoction balance under a specific arrangement of conditions, no further changes in the groupings of reactants and items happen. On the off chance that a change is made in the conditions under which the framework is at harmony, substance change will happen so as to build up another balance. The components that can impact harmony are an adjustment in focus, change in weight (or volume), and change in temperature.
The exothermic process is a process or reaction that involves a release of energy from the system to its surroundings in various forms usually through heat, light, electricity or sound. In the four given choices, when melting a copper, you try to immerse the metal in heaping coals of fire. The metal will absorb the thermal energy coming from the coal, thus, once you retrieve the metal back, light will be emitted from it as well as heat.
Therefore, the answer is B. MELTING OF COPPER