An element occurs as a mixture of isotopes. the atomic mass of an element is based upon

Covalent network solids typically have melting points and boiling points. the chemical formula of a network solid indicates in the molecule.

What overall charge must all compounds have

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