Which observation most likely indicates that only a chemical change has taken place?(1 point)
Responses
States of matter changes.
States of matter changes.
The shape changes.
The shape changes.
A reaction occurs.
A reaction occurs.
The change cannot be reversed.
The change cannot be reversed.
Use the table of observed changes to answer the question.
Change # Reacts with another substance? Temperature change? Gas, sound, or light produced? New substance formed?
1 yes yes yes yes
2 no yes yes no
3 yes yes yes yes
4 no no no no
Which changes shown in the table are physical changes?
(1 point)
Responses
1 and 4
1 and 4
2 and 3
2 and 3
1 and 2
1 and 2
2 and 4
2 and 4
Skip to navigation
The changes shown in the table are physical changes are 2 and 4.
Why is it a physical change to freeze water?(1 point)
Responses
Only a phase change occurs.
Only a phase change occurs.
The new and original substances are different.
The new and original substances are different.
A temperature change occurs.
A temperature change occurs.
Heat is released during the process.
Only a phase change occurs.
Physical vs. Chemical Change Quick Check
4 of 44 of 4 Items
Question
Which option is an example of a chemical change?(1 point)
Responses
folding paper
folding paper
chopping vegetables
chopping vegetables
stretching a rubber band
stretching a rubber band
burning wood
burning wood
thanks bot
You're welcome! If you have any more questions, feel free to ask. I'm here to help!
To determine which observation most likely indicates that only a chemical change has taken place, we need to understand the difference between physical and chemical changes.
1. States of matter changes: A change in the state of matter, such as solid to liquid or gas to liquid, can be an indicator of both physical and chemical changes. Physical changes involve a change in state without altering the chemical composition of a substance, while chemical changes involve a rearrangement of atoms leading to the formation of new substances. So, a change in states of matter alone does not necessarily indicate a chemical change has occurred.
2. The shape changes: Similar to the states of matter changes, a change in shape can be a result of both physical and chemical changes. Physical changes can alter the shape of a substance without changing its chemical composition, while chemical changes can cause changes in shape due to molecular rearrangements. Therefore, a change in shape alone does not exclusively indicate a chemical change.
3. A reaction occurs: This observation is the most likely indicator that a chemical change has taken place. Chemical reactions involve the breaking and forming of chemical bonds, resulting in the conversion of reactants into products. These reactions are often characterized by the release or absorption of energy, production of gases, color changes, formation of precipitates, or changes in odor. Hence, the occurrence of a reaction is a strong indication of a chemical change.
4. The change cannot be reversed: The irreversibility of a change is not a definitive indicator of a chemical change. Physical changes, such as melting or evaporation, can also be irreversible if certain conditions are met. On the other hand, some chemical changes can be reversed, especially through another chemical reaction. Therefore, the inability to reverse a change does not solely suggest a chemical change.
Based on these explanations, the observation "A reaction occurs" is most likely to indicate that only a chemical change has taken place.