Answer:
A. the atomic number
Explanation:
It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth.
Lower fertility and longer lifespans steadily increased the potential labor force relative to the total population
From the given equations, the combustion reaction is;
C₄H₁₂ + 7O₂ --> 4CO₂ + 6H₂O
Combustion reactions are when organic compounds react with O₂ to produce water and CO₂. From the given reactions, C₄H₁₂ is an organic compound that reacts with O₂ to produce water and CO₂.
Therefore this is the only reaction that follows the general equation for combustion.