How many grams of helium would it take to fill a blimp that has a volume of 2,000,000L

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?

Given the data below for the reaction, 2 a + 2 b + 4 c => d + e + 3 f, the reaction is fill in the [ ] order in a, fill in the [ ] order in b, fill in the [ ] order in c and fill in the [ ] order overall. (use the words "first, second, third, fourth" to fill each blank)experimentinitial conc of a, mol/l initial conc of b, mol/l initial conc of c, mol/l initial rate, mol/l.s1 0.1 0.1 0.2 2 x 10-32 0.2 0.3 0.2 6 x 10-33 0.3 0.1 0.2 2 x 10-34 0.4 0.3 0.4 1.2 x 10-2

The density of benzene at 15 °c is 0.8787 g/ml. calculate the mass of 0.1500 l of benzene at this temperature. enter your answer in terms of grams