As a star increases in brightness, which of the following values becomes smaller?

a. density

b. magnitude

c. temperature

d. luminosity

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Ascientist measures the speed of sound in a monatomic gas to be 449 m/s at 20∘c. what is the molar mass of this gas?