The electronic configuration of a particular neutral atom is 1s2 2s2 sp6 3s2 3p2. What is the number of unpaired electrons in this atom?

a. 1
b. 2
c. 3
d. 4
e. 0

The answer is 3. I am not sure why. Does the empty orbital of P count as an unpaired electron?

another question:

the lewis structure for NO3 minus. which looks like this O-N=O and another O single bond attached to it. The total number of ground state resonance structures for this ion is?

Answer is 3. I was wondering is the third resonance structure a hybrid? Thanks.

The electronic configuration of a particular neutral atom is 1s2 2s2 sp6 3s2 3p2. What is the number of unpaired electrons in this atom?

a. 1
b. 2
c. 3
d. 4
e. 0

The answer is 3. I am not sure why. Does the empty orbital of P count as an unpaired electron?
1s2 2s2 sp6 3s2 3p2. ????
what's sp6?
I wonder if sp6 is what 4 year institutions teach but as a community college student let me assume it's 2p6.
P has 3 blanks. when it has 6 arrows in it, the order u draw is up up up and then down down down. In ur question, it says 3p2, so u draw up up. therefore, none of the 3 blanks have pair in it, and 3 is the answer.

1s2 2s2 sp6 3s2 3p2. ????
what's sp6?
I wonder if sp6 is what 4 year institutions teach but as a community college student let me assume it's 2p6.
P has 3 blanks. when it has 6 arrows in it, the order u draw is up up up and then down down down. In ur question, it says 3p2, so u draw up up. therefore, none of the 3 blanks have pair in it, and 3 is the answer.

yeah its actually 2p6. I typed it wrong. anyway, thats what I was thinking as well. Thanks.

The electronic configuration of a particular neutral atom is 1s2 2s2 sp6 3s2 3p2. What is the number of unpaired electrons in this atom?

a. 1
b. 2
c. 3
d. 4
e. 0

The answer is 3. I am not sure why. Does the empty orbital of P count as an unpaired electron?

another question:

the lewis structure for NO3 minus. which looks like this O-N=O and another O single bond attached to it. The total number of ground state resonance structures for this ion is?

Answer is 3. I was wondering is the third resonance structure a hybrid? Thanks.

wait a min. shouldnt the answer be 2. b.c 3p2 has two unpaired electrons in the p orbital

wait a min. shouldnt the answer be 2. b.c 3p2 has two unpaired electrons in the p orbital


yea, it should be 2 ... |^ _|^ _|_ _|

and about the resonance question, it's three because there are 3 o's that have identical electronegativities and therefore contribute equally to a hybrid. basically, the double bond can be moved around to each of the three o's.

I am not quite convinced that empty shells are the same as unpaired electrons. These are energy levels waiting to be "filled".

I would take a different approach. Look at the valance shells:

1s is complete (two electrons).
2s is complete and 2p is complete (octet).
3s is complete, and 3p is not complete (has only two, needs 6 more to complete the octet).

Thus, the only unpaired electrons are two and the answer should be "b" (in my humble opinion).

I am not quite convinced that empty shells are the same as unpaired electrons. These are energy levels waiting to be "filled".

I would take a different approach. Look at the valance shells:

1s is complete (two electrons).
2s is complete and 2p is complete (octet).
3s is complete, and 3p is not complete (has only two, needs 6 more to complete the octet).

Thus, the only unpaired electrons are two and the answer should be "b" (in my humble opinion).

One clarification: above I said that for n=3 (i.e. 3s and 3p), you needed six to complete the octet. Actually, you need 4 more (not six) to complete it. Still, your only available electrons are two. Answer is the same.

well this is from the ADA sample test, and the answer for it was 3. I thought the same as you guys but thats what it is and was wondering if someone on sdn could explain. oh yeah, i already took my test. this question is not on it so no worries.