1. Chapter 2: Study Guide
Have fun studying!

2. What happens to atoms during a chemical change?
Atoms rearrange to form matter with different properties.

3. Give an example of how elements can be separated during a chemical reaction.
Some examples (You’ll need to be able to explain ONE.)
Separating iron from iron ore: When iron ore is heated with carbon, the product is pure iron and carbon dioxide.
Separating a fossil from limestone: Limestone can be broken down by adding vinegar and the fossil will be left unchanged.
Separating lead from a solution: Lead can be removed from a solution that contains water and a compound of iodine. When mixed, lead iodide is formed and can be filtered from the liquid to remove the lead from the solution.

4. Evidence of a chemical change might include the formation of...
gas
new solid (like when two solutions mix and form a precipitate)

5. What does the word “product” mean in a chemical reation?
A product is something made during a chemical reaction

6. Give two examples of products made during a chemical reaction.
Here are some examples you might choose, but there are more:
Rust is formed when oxygen and iron react together.
Hydrogen and oxygen react to form hydrogen peroxide.
Magnesium and oxygen combine to form magnesium oxide.

7. What happens to matter that has gone through only a physical change?
In a physical change, matter can change state, shape, size, etc...but it keeps the same chemical properties.

8. What are some examples of physical changes?
These are some examples, but there are more:
Copper can be hammered into sheets.
Paper can be torn into small pieces.
Potatoes can be cut or shredded.
Hair can be cut.

9. Do the particles in a solid, liquid, or gas have the most energy
Do the particles in a solid, liquid, or gas have the most energy? Which has the least?
Particles in a gas have the most amount of energy. Particles in a solid have the least amount of energy.
The order from least amount of energy to most amount of energy would be:
solid → liquid → gas

10. Explain what a chemical change is.
A chemical change occurs when one type of matter changes into a different type of matter with different properties.

11. Give an example of matter that has gone through a chemical change.
There are many examples, but here are a few:
When wood is burned, the burning wood combines with oxygen and changes into ash and gas.
Cooking a potato changes the chemical properties, therefore, this is evidence of a chemical change.
A burning candle wick would be another example. Melting was is a physical change because it is only changing the state of matter, but burning a candle would be an example of a chemical change.

12. List the properties of solids, liquids, and gases.
solids- particles have a definite shape and volume; particles vibrate in place
liquids- no definite shape (takes shape of the container), but has a definite volume. Particles move more rapidly.
gases- no definite shape or volume. Particles are far apart, rapic movement, spread out evenly in container.

13. Which of the following can only be separated by a chemical process: mixture, solution, matter, or compound?
compound

14. What do scientists use to identify acids and bases?
indicator paper

15. The mass of the reactants is equal to the mass of the product.
What can be said for the mass of reactants versus the mass of products in a chemical reaction? (Law of Conservation of Mass)
The mass of the reactants is equal to the mass of the product.

16. At what temperature does a liquid turn into a solid?
Freezing Point

17. What is condensation? Give one example.
Condensation occurs when gas turns into a liquid. Some examples include:
Dew forms on grass during the night.
Clouds form in the atmoshpere.
Water droplets form on the outside of a glass of ice cold water.

18. Explain what a combination reaction is and give an example.
A combination reaction happens with elements or compounds come together to form new compounds.
Ex: Mg + O → MgO

19. Explain what a decomposition reaction is and give an example.
A decomposition reaction is when compounds split apart to form smaller compounds.
Ex: 2H2O → H2 + H2 + O2

20. Explain what a replacement reaction is and give an example.
A replacement reaction is when compounds split apart and rearrange to join other elements in the compound.
Ex: NaOH + HCl → NaCl + H2O

21. What is the difference between a reactant and a product?
A reactant is a substance used in a chemical reaction.It is always found on the left side of the equation.
A product is what is made during a chemical reaction and is always on the right side of the equation.