Which best describes the purpose of a controlled experiment?
to make sure the results of the experiment support the hypothesis

a. to prevent a dangerous condition resulting from a reaction

b. to examine whether one variable causes a change in another

c. to prevent an undesired change in a variable

In 1980, alfa romeo introduced the first system to smooth a rough idle caused by ignition and camshaft timing changes.

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

Abag of potato chips contains 2.00 l of air when it is sealed at sea level at a pressure of 1.00 atm and a temperature of 20.0 deg c. what will be the volume of the air in the bag if you take it with you, still sealed, to the mountains where the temperature is 7.00 deg c and atmospheric pressure is 70.0 kpa? assume that the bag behaves like a balloon and that the air in the bag is in thermal equilibrium with the outside air.