Based on the Law of Conservation of Matter, what number should be placed in the box to balance the chemical equation below? Group of answer choices

No coefficient is needed.

2

4

3

2

Explanation:

Step 1: RxN

4Al + 3O₂ → Al₂O₃

Step 2: Balance RxN

We have 4 Al's and 6 O₂'s on the reactant side.

We need the same number of Al's and O₂'s on the product side.

4Al + 3O₂ → 2Al₂O₃

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

i would say