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Science Chapter 12
Changes in Matter
Question | Answer |
---|---|
What change below is a chemical change? A. One kind of matter changes phases. B. One kind of matter changes into another kind of matter with different properties. C. One kind of matter keeps its identity and properties. | B |
Which one of the following is an example of combustion? A. a container of milk souring to cottage cheese. B. a dry sponge expanding in water. C. a piece of gray metal turning to rust. D. a log burning in a fire. | D |
What is the product of the reaction Mg + O = MgO | Magnesium Oxide |
What happens to matter during a chemical reaction? | Matter is neither created nor destroyed. |
What bacteria-killing substance did Alexander Fleming accidentally discover? | penicillin |
A scientist used universal indicator paper to test an unknown substance. The indicator paper turned red. What can the scientist conclude about the substance? | It is a strong acid |
If a tent is made from a polymer developed in a chemical lab, what is the name of the polymer? | nylon |
What should you do first before using chemicals at home? | read the directions |
What kind of reaction occurs when two compounds split apart and the parts switch places? | replacement reaction |
Fossils can be found in limestone. What substance can scientists use to separate fossils from limestone? | vinegar |
What is special about treated rubber? | It does not dry or crack during cold weather or melt during warm weather. |
Chemical technology is used in making cement, please explain how. | When cement is mixed with gravel, sand, and water a chemical reaction occurs. The cement sets and makes concrete. Concrete is very hard and durable. It can be used to build bridges and buildings, but gravel and sand by themselves cannot. |
Explain how chemical technology is used with vitamin-enriched foods. | Chemists can add vitamins to food. These vitamins help keep the body healthy. These foods cure or prevent diseases that are caused by a lack of vitamins. |