Electron configurations numbers

Ball color Number of holes Identity of element Electron configuration Number of unpaired electrons... 

In Table 29.1, we summarized our results of electronic structure calculations for Bf -Bjj. We reported symmetry, spectroscopic state, valence electronic configuration, number of 2c-2e peripheral B-B a-bonds, number of delocalized o- and TT-bonds, and assignment of global aromaticity/antiaromaticity. The description of chemical bonding in terms of 2c-2e peripheral B-B a-bonds and nc-2e delocalized a- and tt-bonds was obtained via AdNDP method at... 

In order to analyze the 4f 4f transitions of Pr3"1" in YLF, we first consider only MOs with dominant Pr 4f character among the MOs obtained in section 4.2.4 for the PrFg- cluster. Therefore, the number of possible electron configurations (number of the Slater determinants) is 91 as shown in table 1. 

B... are all Rydberg states with one electron loosely bound to the ionic core, H3 X A. Labels (nl) refer to the united-atom electron configuration numbers that follow them enumerate states in ascending order of energies within each electronic symmetric-species. 

Ion Outer electron configuration Number of unpaired electrons Experimentally measured total magnetic moment/pB Calculated magnetic moment/pB... 

The concept that substances are composed of molecules, and molecules are composed of atoms, can be traced back to chemical antiquity. Nevertheless, in modem molecular electronic stmcture theory, the atomic constituents differ appreciably from the immutable, indivisible particles envisioned by the ancients. Of course, the signature properties of an atom are only indirectly linked to the positively charged nucleus, which carries virtually the entire atomic mass but occupies only an infinitesimally small portion of the apparent atomic volume. We now understand the atom to be composed of the surrounding quantum mechanical distribution of electrons that occupy the characteristic set of orbitals associated with the nucleus in question. Finding the atom in a molecular wavefunction therefore reduces (as in Chapter 2) to the problem of finding the atomic orbitals and the associated electronic configuration (number of electrons occupying each available atomic orbital) around each nuclear center. 

To arrive at the electronic configuration of an atom the appropriate number of electrons are placed in the orbitals in order of energy, the orbitals of lower energy being filled first (Aufbau principle ), subject to the proviso that for a set of equivalent orbitals - say the three p orbitals in a set - the electrons are placed one... 

Hund s rules Rules which describe the electronic configuration of degenerate orbitals in the ground state. The electronic configuration will have the maximum number of unpaired... 

Note. The electronic configuratioa of any element can easily be obtained from the periodic table by adding up the numbers of electrons in the various quantum levels. We can express these in several ways, for example electronic configuration of nickel can be written as ls 2s 2p 3s 3d 4s. or more briefly ( neon core ) 3d 4s, or even more simply as 2. 8. 14. 2... 

The detailed electronic configurations for the elements atomic numbers 5 5-86 can be obtained from the periodic table and are shown below in Table 1.5. 

Give the electronic configurations of elements with atomic numbers. 7,11,17,20,26,30 and 36. 

The element lanthanum (atomic number 57) has the electronic configuration... 

Example The electron configuration for Be is Is lsfi but we write [He]2s where [He] is equivalent to all the electron orbitals in the helium atom. The Letters, s, p, d, and f designate the shape of the orbitals and the superscript gives the number of electrons in that orbital. 

The third period begins with sodium and ends with argon The atomic number Z of sodium is 11 and so a sodium atom has 11 electrons The maximum number of electrons in the Is 2s and 2p orbitals is ten and so the eleventh electron of sodium occupies a 3s orbital The electron configuration of sodium IS 2s 2p 2p 2p is ... 

The electronic configuration for an element s ground state (Table 4.1) is a shorthand representation giving the number of electrons (superscript) found in each of the allowed sublevels (s, p, d, f) above a noble gas core (indicated by brackets). In addition, values for the thermal conductivity, the electrical resistance, and the coefficient of linear thermal expansion are included. 

Name Symbol Atomic number Electronic configuration... 

---