1. Questions

Chemistry

1) What is the atomic # for selenium?
34

2) Write the full electron configuration for selenium following the (n+l) rule?

I am not sure what is meant by n+l

3) write the electron configuration, grouping electrons by their "n" values.

[Ar]3d10 4s2 4p4

Are these correct?

4) What is the number of valence electrons for selenium?
6
what is the number of core electrons?
I do not understand what core electrons are.

5) what is the number of unpaired electrons? Show how you determined this.

i think the answer is two but im not sure why.

6) What is the number of filled shells?
3
7) What is the number of filled orbitals?
4

Are these correct?

Please ignore the first two posts with these questions. My computer was acting up and submitted the question more than once. Sorry.

  1. 👍 0
  2. 👎 0
  3. 👁 2,840
Hannah

  1. 1) What is the atomic # for selenium?
    34
    The atomic number is 34, what else?

    2) Write the full electron configuration for selenium following the (n+l) rule?
    I must admit I don't know what the n+one rule is (although that could be n + ell rule). However the electron configuration is
    [Ar]3d10 4s2 4p4

    I am not sure what is meant by n+l

    3) write the electron configuration, grouping electrons by their "n" values.

    [Ar]3d10 4s2 4p4
    I would write 2,8,18,6 for n = 1,2,3,and 4.

    4) What is the number of valence electrons for selenium?
    6. Those are the 4s2 4p4 and you are correct.
    6
    what is the number of core electrons?
    I do not understand what core electrons are.
    The core electrons are those inside the valence shell; i.e., that will be 34-6 = 28. Another way to look at it is to look at the n shells of 2,8,18,6 and take off the last 6 which leaves 2,8,and 18 = 28.

    5) what is the number of unpaired electrons? Show how you determined this.
    You have 4s2 4p4 in the valence shell (all of the others are paired; i.e., the 2, 8, and 18). The two in 4s2 are paired. That leaves just the 4p4 electrons to worry about. Since there are three p orbitals (the Px, Py, Pz) and Hund's rule says we fill all orbitals BEFORE we start pairing which means we have 1 in Px, 1 in Py, and 1 in Pz. The fourth one must pair up with the 1 already there in Px and there are no more electrons. Therefore, that leaves the last two electrons, 1 in Py and 1 in Pz, unpaired. So the answer is 2 unpaired electrons. So you are right!
    i think the answer is two but im not sure why.

    6) What is the number of filled shells?
    3
    right.
    7) What is the number of filled orbitals?
    4
    I'm not sure what the question means by filled orbitals. Is that completely filled or partially filled. Either way it is a filled orbital. I would count 1s2 as 1 orbital + 2s2 as 1, + 2p6 as 3, + 3s2 as 1, 3p6 as 3 + 3d10 as 5 + 4s2 as 1 + 4p2 as 1 and I'm not counting the last two unpaired since those orbitals are only partially filled. You can add those numbers but I think that is 16. If you interpret the question differently you can adjust the answer.

    1. 👍 1
    2. 👎 1
    DrBob222

  2. Thank you for your help!!!

    1. 👍 0
    2. 👎 0
    Hannah

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    Identify the neutral element represented by this excited-state electron configuration, then write the ground-state electron configuration for that element. Excited State: 1s2 2s2 2p2 3s1 Element Symbol: ? Ground State: ?

  2. chem

    There are eight markers in a full set, but Flora and Frank each only have seven markers.Flora is missing the red marker, and Frank is missing the blue marker.What can they do so that each has a full set of markers? * steal the

  3. Chemistry

    how do i write the complete electron configuration for Ga3+ and Mg2+????????????

  4. Chemistry

    -Calcium chloride contains calcium and chloride ions. Write the ground-state electron configuration for the calcium ion. -Write the ground-state electron configuration for the chloride ion.

  1. AP Chemistry

    Which of the following electron configurations correspond to an excited state? Identify the atoms and write the ground-state electron configuration where appropriate. If the configuration is a noble gas, enter the noble gas in

  2. chemistry

    please help!!! im confused... can you explain to me how period and group trends in atomic radii are related to electron configuration? is it because as you move down the table the atomic radius increases and as you move across the

  3. Chemistry

    Metals lose electrons under certain conditions to attain a noble-gas electron configuration. How many electrons must be lost by the element Ca? Is it 2 e^-? Which noble-gas electron configuration is attained in this process? argon

  4. Configuration

    What is the electronic configuration of carbide C-4? Thought it was 1s2 2s2 sp2. Thanks from Sheryl C is atomic number 6. Electronic configuration of the neutral atom is 1s2, 2s2, 2p2. The carbide ion, C^-4, has four more

  1. chemistry

    Write both the complete electron-configuration notation and the noble-gas notation for each of the elements below a. Na b. Sr c. P

  2. Chemistry

    Did I answer these correctly? 1. What is the total number of principal energy levels or shells in an atom with an atomic number of 30? a. 3 b. 4 c. 5 d. 6 I choose b. 2. The electron configuration of an atom in the ground state is

  3. Chemistry

    Use these answers for questions 4 - 7. (A) 1s2 2s22p5 3s23p5 (B) 1s2 2s22p6 3s23p6 (C) 1s2 2s22p62d10 3s23p6 (D) 1s2 2s22p6 3s23p63d5 (E) 1s2 2s22p6 3s23p63d3 4s2 4. An impossible electronic configuration 5. The ground-state

  4. Chemistry

    Electron configuration for phosphorus is 1s2 2s2 2p6 3s2 3p3. So the number of electron must be 15 , right ? But , what if m = 1 ? Does it effect the number of electron ?

You can view more similar questions or ask a new question.