Lesson 5: Density and Lesson 6: Fat vs. Soap
What is density?
Density is the amount of mass in a given volume.
In Lesson 7: What are reactants?
The starting substances in a reaction.
Difference between boiling and electrolysis?
Which one is a physical and a chemical change?
Boiling is a physical change; electrolysis is a chemical reaction.
Lesson 11: What type of chemical liquid did we use for lab?
Using this sentence frame: Fat reacts with another substance (like ____________) in a chemical reaction.
Fat reacts with another substance (like sodium hydroxide) in a chemical reaction.
What happens to mass during a chemical reaction?
It stays the same.
How do you mathematically calculate the density for this problem?
Length: 9in, Mass: 30 grams, Width: 3in, Volume: 6 mL.
Density = mass ÷ volume.
D= M/V
D= 30grams/6mL
D= 3 g/mL
In Lesson 7: What are products?
The new substances formed/ What did we end up with.
How can you tell if a new substance formed?
The properties are different from the original substances.
Lesson 12: What materials are used to make bioplastic?
Cornstarch, glycerin, water
What is the law of conservation of mass?
Mass cannot be created or destroyed.
Why is density considered a property?
Because it stays the same no matter how much of the substance you have.
In Lesson 7: How can you tell a chemical reaction occurred?
Signs include color change, gas formation, temperature change, or new substance.
Lesson 9: During our Electrolysis Lab, what was our final product?
2 H 2 O → 2 H 2 + O 2
We seperated the water molecule to form hydrogen gas and Oxygen gas
Why is plastic a new substance?
It has new properties different from the starting materials.
Why might mass seem to change in an open system?
Gas can escape.
How are fat and soap different?
They have different properties (like odor, hardness, and solubility in water and oil)
Balance this chemical equation.
__ C3H8 + ___ O2 --> __ CO2 + ___ H2O
_1_ C3H8 + _5_ O2 --> _3_ CO2 + _4_ H2O
Lesson 9: Draw an Electrolysis model
Picture will vary.
What are synthetic materials, and how are they created? Include one example for a natural resource
Synthetic materials (like the bioplastic made in Lesson 12) are substances made by humans through chemical reactions using natural resources such as plant crops, farm animals, or fossil fuels
What is the difference between an open system and a closed system?
In an open system, matter can enter or leave the system.
In a closed system, the reaction is sealed (like in a closed plastic bag or capped bottle) so that nothing can enter or escape, allowing scientists to measure the total mass of all reactants and products accurately
Can two substances have the same volume but different mass?
Yes, because they can have different densities.
In Lesson 8, you observed magnesium burning. Is burning a chemical reaction? Explain
Yes, burning is a chemical reaction. During the process, the atoms of the reactants (like magnesium and oxygen) are rearranged to form a new product; no atoms are created or destroyed, they simply form new arrangements
Lesson 9 & 10: How does the electrolysis of water differ from the boiling of water at the molecular level?
Boiling is a phase change where molecules move faster and spread apart but remain water molecules (H2O).
Electrolysis is a chemical reaction where the water molecules break apart and the atoms combine in new ways to form two new substances: hydrogen gas and oxygen gas
What properties make plastic useful?
Flexible, strong, lightweight, waterproof.
How does a closed system help?
It keeps all matter inside, showing mass stays constant.