Why are planets spherical?

Which statement accurately describes the relationship between air pressure, air density, or altitude? as altitude increases, pressure increases.as altitude increases, air density increases.air pressure and density are lowest at sea level.denser air exerts more pressure than less dense air.

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel

What type(s) of intermolecular forces are expected between ch3ch2cooh molecules? dipole forces, induced dipole forces, hydrogen bonding