Observation and measurement of the environment Prologue Observation and measurement of the environment

Observations are made using your five senses Observations can be made more precisely by using instruments. An inference is a conclusion that is based on observations.

a. Weight is a measure of the pull of gravity. b. Mass (g) is the amount of matter (stuff) in an object. c. Volume (ml or cm3) is the amount of space an object takes up.

Density (g/ml or g/cm3) is the amount of mass in a specific volume of a substance. (D= M÷V ESRT p.1)

Heating a substance makes it less dense, and cooling it makes it denser. Increasing pressure on a substance increases density, decreasing pressure decreases density. Breaking a pure substance into smaller pieces will not change its density.

h. Most substances are most dense as a solid. Water is most dense as a liquid. The density of water is 1 g/ml at 3.98º C (ESRT p.1) Ice is less dense than liquid water.

Human population and pollution. Higher populations tend to result in higher pollution rates.