Chemical Reactions Basics
This happens when substances change into new substances.
👉 Answer: What is a chemical reaction?
This type of reaction releases energy to its surroundings.
What is an exothermic reaction?
In this system, matter can enter or leave.
What is an open system?
These heaters use chemical reactions to heat food without fire.
What are flameless heaters?
Bubbles forming during a reaction usually means this is being produced.
What is a gas?
These are the starting substances in a chemical reaction.
What are reactants?
This type of reaction absorbs energy from its surroundings.
What is an endothermic reaction?
In this system, matter cannot enter or leave.
What is a closed system?
Iron reacting with oxygen in a hand warmer releases this.
What is heat energy?
A temperature increase during a reaction is evidence that energy is being this.
What is released?
These are the substances made after a chemical reaction.
What are products?
A hand warmer getting hot is an example of this type of reaction.
What is an exothermic reaction?
A reaction in a sealed bag is an example of this type of system.
What is a closed system?
This material reacts with oxygen in many hand warmers.
What is iron?
Students measure temperature change to collect this.
What is data?
Which reaction was the best exothermic reaction for cooking food? Use evidence from the lab, such as temperature change, to explain your answer.
The copper sulfate, aluminum, and saltwater reaction was the best exothermic reaction for cooking food. This reaction produced the largest temperature increase, showing that it released the most heat energy. The heat lasted long enough to warm food, making it more useful than the other reactions.
A reaction that feels cold to the touch is most likely this type.
What is an endothermic reaction?
When gas escapes into the air during a reaction, the mass may seem to decrease because it is this type of system.
What is an open system?
This metal is found in MRE flameless heaters and reacts with water to release a lot of heat, explaining why MRE heaters get much hotter than hand warmers, which do not contain it.
What is magnesium?
Comparing different reactions helps students decide which one is this.
What is the most effective reaction?
In a chemical reaction, atoms are rearranged but never created or destroyed. This law explains that.
What is the Law of Conservation of Mass?
Energy in chemical reactions is often transferred as this.
What is heat (thermal energy)?
Even if energy leaves a closed system, this stays the same.
What is mass?
Flameless heaters are useful in emergencies because they do not need this.
What is electricity or fire?
Scientists use evidence to support or reject this.
What is a claim or explanation?