Models are useful because

a) they are very easy to create and destroy.

b) they are very expensive and time consuming to create.

c) they are more accurate than the observing the real phenomenon.

d) they allow us to test possible forces of nature without waiting for them to occur.

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

The atom fluorine generally will become stable through the formation of an ionic chemical compound by accepting electron(s) from another atom. this process will fill its outer energy level of electrons.

How many neutrons does an element have if its atomic number is 50 and its mass number is 166