What is a certain indicator that a molecule is polar

Explain why scientists use shared characteristics to make cladograms.

What is the mass of sodium in 3 moles of sodium chloride

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