When a physical change in a sample occurs, which of the following does not change?
a. shape
b. temperature
c. volume
d. composition

Which is the most likely way an automotive engineer would use chemistry

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

Which statement characterizes synthetic polymers? a. they come from animals and plants. b. they are found in nature. c. they are made in a lab. d. they are components of starch.