Answer:
A. synthesis
Explanation:
The reaction given is a synthesis reaction in which two substances combines to give a product.
In this reaction:
4Fe + 3O₂ → 2Fe₂O₃
The reaction involves the formation of a single product from two or more reactants.
The formation of a compound from union of the constituent elements also falls into this category of reaction.
The answer is; The mercury level first falls then begin to rise rapidly.
This is because even though glass is not a good thermal conductor, the great heat variation causes the glass to gather heat and expand first even before the mercury is reached by the heat. This increases the volume of the lumen of the glass hence causing the mercury level to drop as the volume of the glass increases.
however, as the heat reaches the mercury, it also begins to expand and the levels stop falling and begin to rise.
Halogens and Alkali react aggressively.
