posted by .

1) A Cobalt (II) ion has the electron configuration ____? and is ____?

The answer choices were:
[Ar] 3d5 4s2 diamagnetic
[Ar] 3d7 paramagnetic
[Ar] 3d5 4s2 para
[Ar] 3d7 dia
None of these

I chose [Ar] 3d5 4s2 diamagnetic

2) Choose the corect statement concerning ionization energies.

- The IEof Na is greater than the IE of Cl
- The IE of S is greater than the IE of O
- The IE of Se is greater than the IE of Br
- Of the elements Li, Be, and Na, Li has the smallest IE
- Of the elements K, Ca, and Sr, Ca has the greatest IE.

I chose that the IE of S is greater than the IE of O

Are these correct?

  • Chemistry -

    1). No, you don't have it right.
    Co electron configuration is [Ar]3d74s2.
    To make the Co(II) ion, we remove the two 4s electrons so it now is [Ar]3d7. Since there are five d orbitals, placing 7 electrons can't be done evenly so it must have some unpaired electrons which makes it paramagnetic.
    (Lat me give you the DrBob222 rule for the 3d transition elements. For the +2 ion of ALL of the 3d elements, the number of electrons in the 3d orbitals is the same as the second number of the atomic number. Neat, huh? That means Sc is 1, Ti is 2, V is 3, Cr is 4, Mn is 5, Fe is 6, Co is 7, Ni is 8, Cu is 9, and Zn is 10(not zero))

    O is 13.6, S is 10.4. Look at choice 5.

  • Chemistry -

    for chose 5 Ca is next to K and above Sr so wouldnt Sr be greater?

  • Chemistry -

    K = 4.3
    Ca = 6.1
    Sr = 5.7

  • Chemistry -

    ok where do you get those numbers from?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    Name an element that has 5 electrons in the third energy level. How do i determine the third energy level Row three on the periodic table is third energy level If memory serves me will, it begins with sodium. Ok. iS Krypton the electron …
  2. chem

    There are several exceptions to the octet rule found along the transition and rare earth metal sections. These exceptions are tied to the observed phenomenon that atoms are more stable if orbital systems are either whole or half filled. …
  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 configuration …
  4. Chemistry

    How can you find out how many unpaired electrons are present in gaseous Co3+ ion in its ground state?
  5. Chemistry

    Based on its electronic configuration an atom of manganese would have________unpaired electrons and would be expected to be________. (a)3,paramagnetic (b)2;diamagnetic (c)0,diamagnetic (d)5,paramagnetic
  6. Chemistry

    You write the electron structure like this. 1s2 2s2 2p6 3s2 3p6 3d10 4s1 is the neutral Cu atom. Remove the two outside electrons to make the Cu^+2 ion. That leaves us with 3d9 as the outside and since that is an odd number, one electron …
  7. chemistry final-urgent

    electron configuration of Cr3+? I think is Cr: [Ar] 4s1,3d5 but how about Cr+, Cr2+, Cr3+?
  8. AP Chemistry

    Which of the following electron configurations correspond to an excited state?
  9. math

    Write the first six terms of each of the sequences whose nth term is a)(-3)n { ____, ____, ____, ____ , ____, ____ } b)3 – 4n { ____, ____, ____, ____ , ____, ____ }
  10. Chemistry HELP ASAP

    A Gouy balance is used to determine the magnetic susceptibility of a substance. A strong electromagnet is placed next to the sample, which is on a balance. If the sample is paramagnetic, the mass reading of the balance will increase …

More Similar Questions