Science Study Guide Chapter 3 Open Response Questions

Explain the differences between a mixture and a compound.

a mixture consists of two or more substances that are mixed together but not chemically combined. A compound is a substance formed when two or more elements are chemically combined.

what does it mean for a reaction to be endothermic

An endothermic reaction is a reaction in which energy is taken in.

Is the melting of an ice cube considered a physical change or a chemical change? Explain your reasoning

An ice cube melting is a physical change because it doesn't change the substance it is still water or H2O

Explain the differences in finding the density of a rectangular solid object and finding the density of an irregular solid object?

To find the density for a solid object you must measure its mass and volume and then divide it. To find the volume for an irregular solid you submerge it in a graduated cylinder filled with water.

Explain how you could find out whether or not an unknown liquid is water

You could use the different characteristics of water such as freezing and boiling points, waters density, or using your five scenes