Earth is unique because it is the .

A. only planet with an atmosphere
B. only known planet to support life
C. only planet without rings
D. closest planet to the sun

What is the chemical formula of the following compound

Compare and contrast physical changes with chemical changes.

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?