The solution is lighter in color
The volume of the solution is the same
The metal strip is shiny above the surface of the solution
The metal strip is not shiny below the surface of the solution
The metal strip below the surface of the solution has a dark coat of flaky material
When the metal strip is touched, the flaky material falls off
Based on the observations, can the students correctly conclude that a chemical reaction occurred?
A. Yes, because a new material of a different color formed on part of the metal strip
B. No, because the solution stayed blue
C. Yes, because the volume of the blue solution stayed the same
D. No, because the metal strip was still visible
A. Yes, because a new material of a different color formed on part of the metal strip.
The changes observed on the metal strip suggest that a chemical reaction likely occurred between the metal and the solution. The formation of a new material of a different color, the dark coat of flaky material, and its ability to fall off when touched all support the occurrence of a chemical reaction. The fact that the solution stayed blue and the volume remained the same does not necessarily indicate the absence or presence of a chemical reaction.
To determine whether a chemical reaction occurred based on the given observations, let's analyze each option:
A. Yes, because a new material of a different color formed on part of the metal strip.
This option is partially correct. The observation that a dark coat of flaky material formed on part of the metal strip indicates a potential chemical reaction. However, the change in color alone is not conclusive evidence.
B. No, because the solution stayed blue.
This option is incorrect. The color of the solution staying the same does not necessarily indicate the absence of a chemical reaction. Chemical reactions can often occur without any visible change in color.
C. Yes, because the volume of the blue solution stayed the same.
This option is incorrect. While the volume of the solution remaining the same is relevant to the observation, it is not sufficient to conclude the occurrence of a chemical reaction.
D. No, because the metal strip was still visible.
This option is also incorrect. The visibility of the metal strip alone does not determine whether a chemical reaction has occurred or not.
Considering the given information, the correct answer is A. While a change in color alone is not sufficient evidence for a chemical reaction, the combination of the change in color (lighter in this case) and the formation of a new material (dark coat of flaky material) on part of the metal strip suggests the occurrence of a chemical reaction. It is important to note that additional information or tests would be required to conclusively confirm the presence of a chemical reaction.
To determine whether a chemical reaction occurred based on the observations given, we can evaluate each of the options:
A. Yes, because a new material of a different color formed on part of the metal strip.
- While the metal strip below the surface has a dark coat of flaky material, it is not mentioned that this material is of a different color from the initial metal strip. Therefore, this option cannot be concluded based on the given observations.
B. No, because the solution stayed blue.
- The color of the solution staying the same does not necessarily indicate the absence of a chemical reaction. Some chemical reactions may not result in a color change. Therefore, this option cannot be conclusively determined based on the given observations.
C. Yes, because the volume of the blue solution stayed the same.
- The fact that the volume of the solution remained the same does not provide evidence for or against a chemical reaction occurring. Therefore, this option cannot be concluded based on the given observations.
D. No, because the metal strip was still visible.
- The fact that the metal strip was still visible does not necessarily mean that a chemical reaction did not occur. Some chemical reactions may not result in a visible change to the metal strip. Therefore, this option cannot be conclusively determined based on the given observations.
Based on the given observations, none of the options listed can be concluded as evidence for or against a chemical reaction occurring.