Answer:
D.atom 2 is not the same , because the mass number is different from atoms 1 and 2
3
Explanation:
Here's the balanced equation;
C2H4 + 3O2 → 2CO2 + 2H2O
C ⇒2 C ⇒1 x 2 = 2
H ⇒4 H ⇒2 x 2 = 4
O ⇒3 x 2 = 6 O ⇒ (2 x 2) + (2 x 1) = 6
