Amixture that appears to contain only one substance is a(n) a) always a compound b) heterogeneous mixture c) homogeneous mixture d) always an element

The slope of a velocity time graph over any interval of time gives the during that interval

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water