Light travels one million times faster than sound. How long would light take to travel from one hill to the other?

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Which statement is best described as a atom

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.