Super Science Review Matter 10-20

10. Physical properties tell you all about an object. They let you know if the object is magnetic, if it is a solid, liquid, or gas; and whether the object conducts or insulates electricity, heat, and sound.

11. Volume is the amount of space an object takes up (how large it is). Mass is the amount of matter in an object (how heavy it is). A beach ball has a larger volume than a rock, because it is bigger. But the rock has a larger mass than the beach ball because it is heavier. Mass is not the same as weight –an object on the Moon has the same mass as on Earth, but it will weigh less on the Moon because the Moon has less gravity.

12. Density compares an objects mass to its volume. If an object is denser than water, it will sink. If an object is less dense than water, it will float.

13.There are three states of matter. An object’s state depends on how tightly together its particles are packed and how quickly they move around.

A solid A liquid keeps its shape and volume changes shape but keeps its volume.

A gas changes shape and volume.

As something heats up, its molecules move faster. As it gets hotter, it changes from a solid, to liquid, to gas.

14. The freezing point of water is 0 degrees C (Celsius), when water changes from a liquid to a solid. The boiling point of water is 100 degrees C (Celsius), when water changes from a liquid to a gas. The boiling point and freezing point of other things, like rubbing alcohol or gold, will be different temperatures than water.

15. Metal objects such as iron or steel are magnetic which means they will be attracted to a magnet. To separate a mixture of sand and iron filings, just pull a magnet through it to get out the iron.

16. An object that is a conductor allows things like heat, sound, or electricity to flow through it. A metal frying pan is a good conductor of heat. An object that is an insulator does not allow heat, sound, or electricity to flow through it. It holds it in. A plastic coffee mug is a good insulator of heat.

17. A mixture occurs when two or more pure substances are mixed together. A tossed salad is an example of a mixture. A mixture can always be separated back into its parts.

18. A solution is a special type of mixture in which a solid dissolves into a liquid. This means that the solid “disappears”, or breaks down into tiny particles that you can’t see.

19. To separate a sand and water mixture, pour the mixture through a paper towel to catch the sand. To separate a saltwater solution, you can boil the mixture. When the water is gone, the salt stays behind.

20. A physical change is a change to size, shape or state without changing anything about the substance. A chemical change will cause a new substance to be formed. Clues are: color change, production of bubbles (gas), or heat.