Combustibilty is a: a. physical property b. chemical property c. physical change

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

Explanation for basic character?

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.