can form through changes in the number of . Gains result in negative and losses result in positive . Together makes up

100mg magnesium reacts with 20ml of 1.0m hcl

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.

The bone of a dinosaur and the imprint of a leaf are examples of which kind of fossils? a) index b) body c) amber d) trace