The best description of a light-year is
a) the speed of light in a vacuum.
b) the age of a one-year-old star.
c) the distance light travels in a year.
d) the time it takes light to travel from earth to the sun

What forms when chemical reactions combine pollution with sunlight?

Suppose you have designed a new thermometer called the x thermometer. on the x scale the boiling point of water is 129 ? x and the freezing point of water is 13 ? x. part a at what temperature are the readings on the fahrenheit and x thermometers the same?

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.