Scientist have a data for the density of gas particularls at diffrent levels of the atmosphere. This diagram shows the trend in that data

As air becomes more dense, (select all that apply) o. air weighs less o. gas molecules are closer together o. air is colder o. air weighs more o. gas molecules are further apart o. air is hotter

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.

What is matter? a. anything that has mass and takes up space b. something that has volume and takes up space. c. things that have energy and take up space d. things that take up space but don't have mass