Which of the following is not a mixture

A. air
B. blood
C. orange juice
D. salt

Iknow #2 is d. i just need to know why

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

George is a dalmatian puppy. describe what happens to light that allows you to see george’s black and white coat.