Matter in an ecosystem .

flows only one way
is part of an open system
is eventually lost as heat
is broken down into chemical nutrients

If a planet rotates 360 degrees during a 24 hour time period, what does that tell us about the planet? a. the middle of the planet is in darkness b. the seasons on the planet vary every day. c. the planet runs on a 12-hour time clock. d. the temperature on the planet varies daily.

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?