What was the major event that began this science unit?
The Hindenburg Explosion
What gas was used to lift the Hindenburg into the air (what gas was it filled with)?
Hydrogen
What do we call the starting substances in a chemical reaction?
Reactants
What are the tiny building blocks that make up matter?
Atoms
What does the law of conservation of matter state?
Matter is not created or destroyed during a chemical reaction; atoms are rearranged.
What were the two main possible causes investigated in the unit?
Hydrogen gas and the materials/paint on the airship
What gas in the air is needed for hydrogen to burn?
Oxygen
What do we call the new substances formed during a chemical reaction?
Products
What do we call two or more atoms chemically bonded together?
Molecules
In a closed system, what should happen to the total mass during a chemical reaction?
The total mass should remain the same.
What is a claim in science?
A statement that answers a scientific question
What is the scientific term for a substance's ability to burn?
Flammability
Hydrogen reacts with oxygen to form water. Is water a reactant or a product?
Product
In the formula 4H₂O, how many hydrogen atoms are there?
8 Hydrogen Atoms
In the Mass Mix-up lab, why was the balloon important?
It trapped the gas produced so the gas remained part of the measured system. It also made it a closed system for the experiment.
What should scientists use to support a claim about what caused an event?
Evidence from observations, experiments, or data
Why can't a fire start in an environment of just hydrogen?
It needs oxygen and an ignition source to start.
Name one observation that may provide evidence that a chemical reaction occurred.
Gas production (bubbles), a temperature change, a color change, or the formation of a new solid
How many oxygen atoms are in 24H₂O?
24 Oxygen Atoms
A chemical reaction causes the temperature of its surroundings to increase. Is energy being absorbed from or released into the surroundings?
Energy is being released into the surroundings.
Why might scientists change their original explanation of the Hindenburg explosion as they learn more?
Because new evidence may support a different explanation or require them to revise their claim.
A candle flame goes out when a jar covers it. What does this suggest about the role of oxygen in burning?
The available oxygen becomes insufficient to sustain combustion.
Hydrogen and oxygen react to form water. Explain how the substances change during this reaction.
The hydrogen and oxygen atoms rearrange and bond in a new way to form water molecules.
In a chemical reaction, what happens to the atoms when reactants become products?
The atoms rearrange to form new molecules, but the total number of each type of atom stays the same.
Steel wool rusts through a chemical reaction with oxygen. Is energy released or absorbed overall, and how can scientists investigate this?
Energy is released overall. Scientists can investigate temperature changes and other evidence, recognizing that rusting releases energy slowly.