How did the elements begin to stratify?

How does the release of trapped gases in magma cause a volcano to erupt? a. they push the magma up the pipe and then are reabsorbed into the magma chamber. b. they cause the magma to change chemically into lava. c. the gases form vents that allow the magma to flow out. d. the gases rush out and carry the magma with them.

How do you date a sample of rock that you suspect as being one of the earliest on earth

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.