Which of the following items best embodies the physical property of conductivity?
a. a diamond's ability to scratch glass.
b. a white cotton shirt that reflects all wavelengths of light.
c. a copper skillet that easily transmits thermal energy.
d. gold's ability to be fashioned into intricate pieces of jewelry

Awelder using a tank of volume 7.50×10^-2 m^3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.30×10^5 pa and temperature of 37.1 ∘c. the tank has a small leak, and in time some of the oxygen leaks out. on a day when the temperature is 23.1 ∘c, the gauge pressure of the oxygen in the tank is 2.00×10^5 pa . a) find the initial mass of oxygen. b) find the mass of oxygen that has leaked out.