Chemthink Questions

Answers to questions:

1. Reactants are the starting point for a reaction.

2. The ending materials in a chemical reaction are called products.

3. The arrow indicates the change of the chemical reaction from the start to finish.

4. Rearrangement.

5. Breaking, Forming.

6. Atoms.

7. Missing atoms, New atoms.

8. Rearrange the bonds.

9. 2, 2, 1, 1.

10. 2, 1, 2.

4 hydrogen atoms 4 hydrogen atoms

2 oxygen atoms 2 oxygen atoms

11. The law of conservation of mass.

12. Atoms, Mass.

13. 1, 1, 2.

14. Cu atoms - 1 Cu atoms- 1

O atoms - 2 O atoms - 1

15. Same number of O atoms, O.

16. Cu, O2, Cu

17. 2, 1, 2.

Cu - 2 Cu-2

O-2 O-2

18. 1, 2, 2, 1

19. 1, 3, 2.

20. 2, 2, 3

21. 4, 3, 2.

Summary:

1. Breaking bonds, making bonds, or both.

2. The atoms must be present before and after the chemical reaction.

3. Coefficients, atom.