A particular refrigerant cools by evaporating liquefied CCl 2F 2. How many kg of the liquid must be evaporated to freeze a tray of water to ice (at zero degrees C)? The tray contains 525 grams water. Molar heat of fusion of ice = 6.01 kJ/mol. Molar heat of vaporization of CCl 2F 2 = 17.4 kJ/mole

Which object forms when a supergiant runs out of fuel? a red giant a black hole a white dwarf a neutron star

How does a scientist the government? a. the scientist tells people in society what to do. b. the scientist determines the policies that the government spends money on. c. the scientist provides unbiased information to the government. d. the scientist makes laws based on his or her research results.

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.