Liquid helium is stored at its boiling-point temperature of 4.2 k in a spherical container (r = 0.30 m). the container is a perfect blackbody radiator. the container is surrounded by a spherical shield whose temperature is 74 k. a vacuum exists in the space between the container and the shield. the latent heat of vaporization for helium is 2.1 104 j/kg. what mass of liquid helium boils away through a venting valve in one hour?

answer and explanation;

composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock while texture refers to the size and arrangement of the minerals or grains that make up a rock. both composition and texture can be used to classify rocks, such as igneous rocks. texture describes how the rock became solid or crystallized from liquid, melted rock. composition of a rock describes the minerals that make up a particular rock.