The bonds that hold atoms together in compounds are called?

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.

No copying 15 pts how does a free-body diagram tell you about the net force on an object?

How can a mixture of salt water be separated into salt and water