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
Answer:
2 only
Explanation:
Electrons are filled in atoms according to the Aufbau principle. Electrons are filled into lower energy orbital before the filling of higher energy orbitals and this sequence must be followed in filling electron orbitals.
The order of arrangement of energy levels may be shown as follows; 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p. This implies that 4f>6s, hence 6s is filled before 4f.
Also, the 6p level > 5d level hence this is the correct option. You must fill the 5d level before you feel the 6p level.
Good conductor of electricity
Answer:
the answer I's the first one