Which of these represents what the ozone layer does for our planet

A- it acts like a window
B- it acts like a shield
C- it enhances the EM waves from the sun
D- it does nothing at all

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

Why are people not able to skip a dive to the deepest part of the ocean