Which statement best explains why different gases effuse at different rates? \
at a given pressure, gas particles with smaller masses move faster.
at a given pressure, gas particles with smaller masses move slower.
at a given temperature, gas particles with smaller masses move faster.
at a given temperature, gas particles with smaller masses move slower

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?

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

15) a substance used in manufacturing gasoline consists of finely divided platinum supported on an inert solid. suppose that the platinum is formed by the high temperature reaction between platinum (iv) oxide and hydrogen gas. the other product is water. a) write and balance the equation b) how many grams of hydrogen are needed to produce 1.0 g of platinum metal? c) how many moles of water are produced at the same time? how many grams? ( show work, .)