Geocentric theory proposes that all objects including the moon, sun, stars orbit around the Earth while the heliocentric theory proposes that all other objects including the Earth, moon, and stars move around the Sun.

When you see distant streetlights through smog, they look dimmer and redder than they do normally. but when you see the same streetlights through fog or falling snow, they look dimmer but not redder. use your knowledge of the interstellar medium to discuss the relative sizes of the particles in smog, fog, and snowstorms compared to the wavelength of light.

How many astronauts have walked on the moon?

Five structural isomers have the formula c6h14. where needed, draw the structure and give the iupac name of all five isomers.