Answer:
The answer to your question is the letter D. 12
Explanation:
Unbalanced chemical reaction
Al(OH)₃ + H₂SO₄ ⇒ Al₂(SO₄)₃ + H₂O
Reactants Elements Products
1 Al 2
1 S 3
5 H 2
7 O 13
Balanced chemical reaction
2Al(OH)₃ + 3H₂SO₄ ⇒ Al₂(SO₄)₃ + 6H₂O
Reactants Elements Products
2 Al 2
3 S 3
12 H 12
18 O 18
Sum up the coefficients
Result = 2 + 3 + 1 + 6
= 12
T A R G E T or T J M A X X
Carbon-13 has 7 neutrons and carbon-12 has 6 neutrons. Carbon-12 is the most common isotope of carbon. Carbon-14 is radioactive and very rare. The symbols for the isotopes of carbon atoms shown here indicate they each have six protons but mass numbers of 14, 13 and 12.