The energies, E, for the first few states of an unknown element are shown here in arbitrary units:

n= 1, E=-21
n=2, E=-9
n=3, E=-4
n=4, E=-3
...,...
infinity, 0

A gaseous sample of this element is bombarded by photons of various energies (in these same units). Match each photon to the result of its absorption (or lack thereof) by an n=1 electron.

Photon/Energy:
A/21
B/17
C/15
D/12

Possible answers:
n=1 to n=2
n=1 to n=3
n=1 to n=4
electron ejected
not absorbed

I think the A/21 is electron ejected, but I don't know how to figure the rest...

4 answers

If I could draw a diagram but I can't. Let me try to use periods as spaces.
E = k/N2

.....1.....2.....3.....4.....inf
E = -21...-9....-4....-3......0

In going from n = 1 to n = 2 we have dE = 13
Going from 1 to 3 we have dE = 17
Going from 1 to 4 we have dE = 18
Going form 1 to inf we have dE = 21
Match them up.
A is 21 so that must be the one ejected; i.e., ionized.
B is 17 so that must be 1 to 3
C and D are not absorbed.

Check my thinking
A= ejected
B=1->3
C=not absorbed
D=1->2
A= ejected
B=1-3
C= not absorbed
D=1-2
Name the following compounds:

CH3COONa

(NH4)2SO4

Mg(H2PO4)2