For an observer who stays in one spot when the source of a sound is moving,

the sound wave's:

O

A. frequency changes.

O

B. amplitude decreases.

O

C. speed increases.

O

D. amplitude increases.

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.

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate

Convert .347 kilometers to miles show your work