500
actually 300.
1-99= 20
100-199=20
200-299=120
300-399=20
400-499=20
500-599=20
600-699=20
700-799=20
800-899=20
900-999=20
1-999= 300
300 sir
There is only one 2s orbital in an atom.
310.
25 of them
2000
100 2s for the hundreds digit of 200-30010 2s for the tens digit of 220-23010 2s for the ones digit of 200-300________________________________120 '2s'
unknown
39
1
36
20 of them.
26