Answer:
B) a substance's color and odor changed Explanation: A signal that a chemical change has occurred is when its odor (its smell) or its appearance has changed.
Cu + S ---> CuS
by reaction 1 mol 1 mol
from the problem 0.25 mol 0.25 mol
0.25 mol Cu
Elements are ordered from left to right, increasing atomic number as they go. The periodic table allows us to find out and predict things about elements that haven’t been discovered yet!
Physical Change: It is a type of change in which matter changes its physical state like shape, size but is not transformed into another substance. It is usually a reversible process.
Chemical Change: It is a type of change in which the rearrangement of atoms of one or more than one substance is involved. and it changes its chemical composition that is there is a formation of at least one new substance. It is usually an irreversible process.
Now, keeping in mind the definitions, we can easily classify the examples in the question as physical or chemical change.
7. Chemical Change
8. Chemical Change
9. Physical Change
10. Chemical Change
11. Physical Change
12. Physical Change
13. Chemical Change
14. Physical Change
15. Chemical Change
16. Physical Change
17. Chemical Change
18. Chemical Change
19. Physical Change
20. Physical Change
21. Chemical Change
22. Physical Change
23. Chemical Change
24. Chemical Change
25. Physical Change
The SI unit for measuring distance is the
meter.
I attached a table of SI measurements for you :)
Hope this helped!
