The properties of elements are determined by their group/family. Usually, its the area they are located on the periodic table. The valence electrons also determine reactivity, etc.
Answer:
B i think
Explanation:
google lol but could be wrong
2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O
2.35 mol C2H2 - x mol O2
2 mol C2H2 - 5 mol O2

answer: 5.875 mol