The half-life of an imaginary element is 50 seconds. How many grams of sample remain in a 30 gram sample after 250 seconds?

V1t2 = v2t1 is an expression of who’s law

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

Nonpoint source pollution is difficult to control because it