Scientists are studying how substance A and substance B react. When substance A and B are mixed, a substance different from A and B floats to the top of the solution. This is evidence that a(n)
Question 7 options:
chemical change occurred.
irreversible change occurred.
physical change occurred.
endothermic change occurred.
Answers
Correct answer is Chemical change as Occurred.
Reason :
When a chemical reaction occurs one of the following thing happens :
1. A new product is formed which is totally different from reactants.
2. State of the product might change.
3. Evolution of gas.
4. A precipitate might be formed.
5. Heat might be released or absorbed .
So in the given question, we observe that when substance A and B reacts a new substance different from A and B is formed . Hence it is chemical change.
Here is the required answer: Scientists are studying how substance A and substance B react.
When substance A and B are mixed, a substance different from A and B floats to the top of the solution.
This is evidence that a chemical change occurred.
Therefore, option first is correct among other 3 chocies.