leslie incorrectly balances an equation as 2c4h10 + 12o2 → 8co2 + 10h2o.

which coefficient should she change?
2
8
10
12

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium