List all possible oxidation numbers for the elements. 21. Al 22. Bi
23. Ni
24. Xe
25. Pb

21. Al (Aluminium)

+3 (most common), -1, -2, +1, +2

22. Bi (Bismuth)

+3 (most common), -3, -2, -1, +1, +2, +4, +5

23. Ni (Nickel)

+2 (most common), -2, -1, 0,+1, +3, +4

24. Xe (Xenon)

0 (most common), +1, +2, +4, +6, +8

25. Pb (Lead)

+2 (most common), +4 (most common), -4, -2, -1, +1, +3

Explanation:

Now we proceed to present the answers for each element:

21. Al (Aluminium)

+3 (most common), -1, -2, +1, +2

22. Bi (Bismuth)

+3 (most common), -3, -2, -1, +1, +2, +4, +5

23. Ni (Nickel)

+2 (most common), -2, -1, 0,+1, +3, +4

24. Xe (Xenon)

0 (most common), +1, +2, +4, +6, +8

25. Pb (Lead)

+2 (most common), +4 (most common), -4, -2, -1, +1, +3