What type of galaxy is pictured below?

a) irregular
b) spiral
c) lens
d) elliptical

Find the empirical formula of each of the following compounds. given mass or for each element in a sample of the compound 3,611 g ca; 6.389 g c1

There are main groups in the modern periodic table of elements

Transportation is the largest single source of air pollution in the united states. air pollution can harm the environment and human health. which technology could offer a solution to this problem? mufflers that reduce noise motors that run on electricity tires that improve gas mileage