Which coefficients will balance the following chemical equation? C7H16(g) + O2(g) → CO2(g) + H2O(l)

2, 12, 6, 10
2, 12, 6, 10

2, 11, 7, 8
2, 11, 7, 8

2,

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

How many grams of aluminum will there be in 98g of al2o3?

Is powdered sports drink ionic or covalent ? 10pts !