## tywower one year ago Which of the following is a possible set of quantum numbers for an electron? (1, 1, 0, +½) (1, 0, 0, +½) (3, 2, 3, -½) (3, -1, 0, -½)

1. tywower

@UnkleRhaukus

2. tywower

@ganeshie8

3. tywower

@Australopithecus

4. tywower

@perl

5. tywower

HIII UNCLE RHAUKUS

6. UnkleRhaukus

HI !

7. tywower

*UNKLE

8. tywower

i'm kinda lost on this question :(

9. UnkleRhaukus

lets look at the QM numbers one at a time

10. UnkleRhaukus

the first one is n ; the principal QM, it represent the electron shell n has to be some positive natural number

11. UnkleRhaukus

all the n's in the options are valid

12. UnkleRhaukus

the second QN , $$\ell$$; is the subshell this can be values from 0 up n-1

13. UnkleRhaukus

this makes of two of the options invalid, can you tell me which two?

14. UnkleRhaukus

Yes the options have the second term: either not greater than 0, or not less than n so they can't be right

15. UnkleRhaukus

we have these options left: (1, 0, 0, +½) (3, 2, 3, -½)

16. UnkleRhaukus

the third quantum number is the magnetic quantum number, $$m_\ell$$ this can be any integer less than or equal in magnitude to $$\ell$$ _____ for example if $$n$$ was 5 and $$ell$$ was 4, $$m_{\ell}$$ could be -4, -3, -2, -1, 0 , 1, 2, 3, or 4

17. UnkleRhaukus

$$ell$$*$$\ell$$

18. UnkleRhaukus

The final quantum number is related to the spin of the electron, $$m_s$$ this can only take values of: $$+\tfrac12$$ or $$-\tfrac12$$

19. UnkleRhaukus

Only one of the options has both: the second QN less than the first (but non-negative), and the third QN less than or equal to (in magnitude) the second

20. UnkleRhaukus

Which option is this @tywower?

21. tywower

the third one

22. UnkleRhaukus

nope, the third option has the third QN greater than (in magnitude) the second QN

23. tywower

can u explain why it's the second one :)

24. UnkleRhaukus

A. (1, 1, 0, +½) not this one, $$\ell\not<n$$ (1, 0, 0, +½) maybe (3, 2, 3, -½) not this one, $$|m_\ell|\not\leq \ell$$ (3, -1, 0, -½) not this one either, $$\ell\not>0$$

25. tywower

thank you so much @UnkleRhaukus u are absolutley amazing! can u help me with some more?

26. UnkleRhaukus

more Q numbers?

27. tywower

No, they're just questions I'm having a hard time understanding :)

28. UnkleRhaukus

ok,

29. tywower

Such as: Which of the following pairs of elements could possibly be found in the same group on the periodic table? A is an alkali metal, B forms a 1- ion. A has the atomic number 20, B forms a 2- ion. A is a noble gas, B has seven valence electrons. A forms a -3 ion, B has five valence electrons.

30. UnkleRhaukus

What kind of ions do metals form? + or - ?

31. tywower

+

32. UnkleRhaukus

so could the first option possibly be true?

33. tywower

maybe

34. UnkleRhaukus

elements in a group (column) always form the same kind of ions e.g. Mg^+, Ca^+, are ions of group II, F^-, Cl^-, Br^-, are ions of group VII

35. UnkleRhaukus

If A and B are of the same group, and A (a metal) forms ^+ ions, could B form ^- ions?

36. UnkleRhaukus

@tywower

37. tywower

@UnkleRhaukus

38. tywower

@UnkleRhaukus

39. UnkleRhaukus

@tywower

40. tywower

sorry i got distracted

41. tywower

lol

42. UnkleRhaukus

@tywower

43. tywower

@UnkleRhaukus it's the last one right

44. UnkleRhaukus

perhaps