What is the property of liquids to mix in all proportions and form a homogenous solution

How to convert a density of 0.791g/cm3 to lb/ft3

Which set of characteristics best describes igneous rock? a) largest type of rock, made of organic matter, hardest type of rock b) least abundant type of rock, made of other rocks, made mostly of minerals c) found on all continents, contains wavy bands of stripes, contains fossils d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Is this correct if not can u correct me