A student put 2 mL of distilled water into a test tube and then added 1 drop of an unknown sample. They mixed the contents within the test tube by gently tapping the side of the test tube. The water and unknown sample formed a homogeneous solution as the unknown dissolved in the water. What compound is most likely the unknown

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Stage in which a star’s outer layers have started to cool and grow outward?

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.