Is the density of water a physical or chemical change?

Much of the general structure and physical properties of the interior of the earth are inferred from: a)deep oil and gas bore holes b)geologic investigations c)analysis of seismic waves d) study of volcanoes

Scientific evidence tells us that the cause of earths four season is the tilt of earth as it revolves around the sun. the student is instructed to illustrate this information in a science notebook. how will the student illiterate winter in the northern hemisphere?

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?