The chemical formula for emerald is Be3Al2(SiO3)6. An emerald can be described as a pure substance because it is a compound.
a pure substance because it is an element.
an impure substance because it is chemically combined.
an impure substance because it is a mixture.

Name the following chemical compound: ca(c2h3o2)2

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

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3