Which unknowns contained a lipid?

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Acompound has the molecular formula c3h8. which class of organic compounds does it belong to?

Organisms are classified as producer or consumers according to the way they ?