Chapter 2: Study GuideHave fun studying!

What happens to atoms during a chemical change?

Atoms rearrange to form matter with different properties.

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.

Evidence of a chemical change might include the formation of...● gas● new solid (like when two solutions mix

and form a precipitate)

What does the word “product” mean in a chemical reation?

A product is something made during a chemical reaction

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.

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.

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.

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

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.

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.

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.

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

compound

What do scientists use to identify acids and bases?

indicator paper

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.

At what temperature does a liquid turn into a solid?

Freezing Point

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.

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

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

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

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.