Help-Science question,,,, I wasn't there when they had this question taken up,,?

Question

Science question,,,, I wasn't there when they had this question taken up,, and when it was teached,,,
science power 10 (by McGraw-Hill Ryerson), pag 244
section= Factors Affecting Chemical Reaction Rate,

2. In each part of this investigation, how did you know that a chemical reaction had occured?

4.Based on your conclustions, suggest least one reason why an automobile is more difficult to start in the winter.

4.What happens to the molecules in food when food is put in a refrigerator?

5.Why does kindling make it easier to start a fire?

9.Thinking Critically- Why are important artifacts, such as preserved body, stored under airtight, temperature-controlled conditions?

-Please answer these questions,,, even though i was gone to march break for 2week, my teachers wants answer for these questions, and i was gone so i donnot know, p

Answer 1

2) A chemical reaction may cause a change in color, new properties in the products, bubbles to form, something to burn.

4) Gas vaporpressure is lower due to cold temps. Water vapor from air condenses and gets into the gas. Oil loses viscosity and thickens so parts don't move as easily.

4) When materials are cooled they give off some of their kinetic energy. This means they move slower. The slower the particles move the closer they get to each other.

5) More surface area for the air (and oxygen) to surround the wood and allow the fire to burn easier.

9) Air-tight to prevent the flow of air to dry out the material, or to prevent the air from carrying in bacteria to decompose it. Temperature controled to stop the molecules from moving too fast and destroying the material.

Answer 2

Sweet pea. Apart from the first questions which we have not seen the investigation so can not offer a conclusion. These are reasonably easy questions and I think you need to answer them yourself. Google some of the point. Read a little about it. You need to do this. I'm sorry. Good luck :0)