Why might different types of fossils be found in rock layers that come before and after a rock layer that contains no fossils?

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17

Which of these features are formed when hot groundwater is forced out through cracks in the earth's surface?

Mercury metal is poured into a graduated cylinder that holds exactly 22.5 ml the mercury used to fill the cylinder mass in 306.0 g from this information calculate the density of mercury