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
2 and 3
2 and 3
1 and 2
1 and 2
2 and 4
2 and 4
1 and 4
Physical changes are typically characterized by changes in the state or appearance of a substance without altering its chemical composition. Such changes usually do not involve a reaction with another substance, the production of a new substance, or the release of gas, sound, or light as a result of a chemical reaction.
Based on the information provided in the table:
Change #1 is not a physical change because it involves a substance reacting with another substance, a temperature change, production of gas, sound, or light, and the formation of a new substance.
Change #2 might seem tricky because it states there's no reaction with another substance and no new substance is formed. There is a temperature change and the production of gas, sound, or light, which might suggest a chemical change, but since no new substance is formed, this could represent a physical change where heat or light is involved without a chemical reaction, such as boiling water where steam and heat are produced but the substance remains water (H2O).
Change #3 is not a physical change because it involves a reaction with another substance, a temperature change, production of gas, sound, or light, and the formation of a new substance.
Change #4 appears to be a physical change because there is no reaction with another substance, no temperature change, no production of gas, sound, or light, and no new substance formed.
Therefore, the changes that are physical changes are 2 and 4.
are you sure?
Apologies for any confusion earlier. Let me re-evaluate the information given in the table:
A chemical change typically involves:
- Reacting with another substance
- A significant temperature change
- Gas, sound, or light produced
- New substance formed
A physical change usually does not create a new substance and can often be reversed. Let's reassess each change based on this:
Change #1:
- Reacts with another substance? Yes
- Temperature change? Yes
- Gas, sound, or light produced? Yes
- New substance formed? Yes
This indicates a chemical change, not a physical one.
Change #2:
- Reacts with another substance? No
- Temperature change? Yes
- Gas, sound, or light produced? Yes
- New substance formed? No
Although there is a temperature change and production of gas, sound, or light, there isn't the formation of a new substance or a reaction with another substance. This might suggest a physical change, depending on the context. For example, a temperature change could simply be heating or cooling, and the production of light could be from a physical process like the glowing of a lightbulb. However, given the lack of context here and the combination of temperature change and some form of emission (gas, sound, or light), it's not entirely clear if this should be considered a physical change absent more information.
Change #3:
- Reacts with another substance? Yes
- Temperature change? Yes
- Gas, sound, or light produced? Yes
- New substance formed? Yes
This is clearly a chemical change, not a physical one.
Change #4:
- Reacts with another substance? No
- Temperature change? No
- Gas, sound, or light produced? No
- New substance formed? No
This indicates a physical change as none of the typical indicators of a chemical change are present.
Based on the typically accepted definitions, without additional context, we would say that Change #2 has elements that are ambiguous as to whether it represents a physical or chemical change, but Change #4 clearly represents a physical change. It's important to note that without specific details about what the changes involve, there is a degree of interpretation required to determine the correct classification.
Given a standard interpretation, Change #4 is certainly a physical change. Change #2 might be a physical change, but some might argue the temperature change and production could suggest a chemical process, depending on the specifics.
Therefore, assuming standard definitions apply and without further information, the safest choice would be that Change #4 is a physical change. Change #2's classification is less clear, but leaning towards the assumption of a physical change is reasonable, giving us "2 and 4" as the most likely answer.
To determine which changes shown in the table are physical changes, we need to understand the characteristics of physical changes.
A physical change is a change in which the substance retains its original chemical composition. In such changes, the particles of the substance may change their arrangement, but no new substance is formed.
Let's analyze each change in the table:
1. Change #1: It reacts with another substance, shows a temperature change, produces gas, sound, or light, and a new substance is formed. Therefore, this is not a physical change.
2. Change #2: It does not react with another substance but shows a temperature change, produces gas, sound, or light. No new substance is formed. Hence, this change can be considered a physical change.
3. Change #3: Like Change #1, it reacts with another substance, shows a temperature change, produces gas, sound, or light, and a new substance is formed. Therefore, this is not a physical change.
4. Change #4: It does not react with another substance, shows no temperature change, and does not produce gas, sound, or light. No new substance is formed either. This change is consistent with a physical change.
Based on this analysis, we can conclude that changes #2 and #4 in the table are physical changes. Therefore, the correct answer is "2 and 4."