Which of the following is a chemical change

a.) water vapor in the air turns to liquid water in the form of rain.
b.) the oxygen in the air forms ozone in presence of uv rays.
c.) dust spit particles being suspended in the air.
d.) sulphuric dioxide being released in the air.

The pressure in a fluid is affected by which characteristics of that fluid

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)

Which of the following molecules is polar? c3h7oh c2h5cooh