Electronic configurations of atoms

Section 1.1 A review of some fundamental knowledge about atoms and electrons leads to a discussion of wave functions, orbitals, and the electron configurations of atoms. Neutral atoms have as many electrons as the number of protons in the nucleus. These electrons occupy orbitals in order of increasing energy, with no more than two electrons in any one orbital. The most frequently encountered atomic orbitals in this text are 5 orbitals (spherically symmetrical) and p orbitals ( dumbbell -shaped). 

When assigning electrons to MOs, the same rules apply as for writing electron configurations of atoms. Electrons fill the MOs in order of increasing orbital energy, and the... 

In this section, you will learn how to predict the electron configurations of atoms of elements. There are a couple of different ways of doing this, which we consider in turn. It should be emphasized that, throughout this discussion, we refer to isolated gaseous atoms in the ground state. (In excited states, one or more electrons are promoted to a higher energy level)... 

From Figure 6.8 it is possible to predict the electron configurations of atoms of elements with atomic numbers 1 through 36. Because an s sublevel can hold only two electrons, the Is is filled at helium (Is2). With lithium (Z = 3), the third electron has to enter a new sublevel This is the 2s, the lowest sublevel of the second principal energy level. Lithium has one electron in this sublevel (ls s1)- With beryllium (Z = 4), the 2s sublevel is filled (ls22s2). The next six elements fill the 2p sublevel. Their electron configurations are... 

The periodic table and electron configurations. The periodic table can be used to deduce the electron configurations of atoms. The color code in the figure shows the energy sublevels being filled across each period. Elements marked with asterisks have electron configurations slightly different from those predicted by the table. 

This paper deals with some questions in the foundations of chemistry. The atomic orbital (or electronic configuration) model is examined, with regards to both its origins and current usage. I explore the question of whether the commonly-used electronic configuration of atoms have any basis in quantum mechanics as is often claimed particularly in chemical education. 

TABLE 2.1 Some Typical Electron Configurations of Atoms and the Ions They Form ... 

What Do We Need to Know Already This chapter draws on many of the principles introduced in the preceding chapters. In particular, it makes use of the electron configurations of atoms and ions (Sections 1.13 and 2.1) and the classification of species as Lewis acids and bases (Section 10.2). Molecular orbital theory (Sections 3.8 through 3.12) plays an important role in Section 16.12. 

The electron configurations of atomic ions are written using the same procedure as for neutral atoms, taking into account the proper number of electrons. An anion has one additional electron for each unit of negative charge. A cation has one fewer electron for each unit of positive charge. 

Quantum numbers The four quantum numbers—principal, angular momentum, magnetic, and spin—arise from solutions to the wave equation and govern the electron configuration of atoms. 

Several facts are apparent from this graph. Although we have not yet dealt with the topic of electron configuration of atoms, you should be somewhat familiar with this topic from earlier chemistry courses. We will make use of some of the ideas that deal with electron shells here but delay presenting the details until later. 

Despite many approximations the Herman-Skillman results compare well with experimental values and the program still is a useful tool for calculations related to the electronic configurations of atoms. 

When atoms get closer to each other, they may become held together by forces of attraction called chemical bonds. To explain why this happens, we need to understand more about the electron configurations of atoms. 

The Mossbauer effect, although not a substitute for other analytical methods such as x-ray diffraction, can be used to obtain several kinds of structural information about solids. In favorable cases, it is possible to obtain rather detailed information about the electronic configuration of atoms and the local symmetry of their sites by measuring the isomer shift and quadrupole splitting. If more than one valence state of a given atom is present, a semiquantitative determination of the amount of each kind is possible. In solid solutions, the amount of local or long range order can be estimated, and in certain defect structures the relation between the active atoms and the defects can be studied. 

Describe, using examples, the relationship between the four quantum numbers and the electron configurations of atoms. 

Watch the video clips at www.brightredbooks. net. These will help you understand how to use the Pauli exclusion principle, the aufbau principle and Hund s rule to write electronic configurations of atoms. 

The electronic configuration of atomic oxygen is Is, 2s, 2px, 2py 2pz in its ground state ( P2), so that two unpaired electrons occupy the upper levels. In molecular O2, which is more stable because of the bond formation energy, which is —493.4 kJ mol , the molecular orbital of the ground state is ... 

The Electronic Configurations of Atoms the Periodic Classification of the Elements... 

Table 2-4.— Electron Configuration of Atoms in Their Normal States... 

Table 5. Electronic configuration of atoms in normal state ...

The prefix number designates the value of n. Each line in the diagram represents one energy level, each can accommodate two electrons of opposite spin. The ground state electron configuration of atoms can now be determined, if the total number of electrons is given. To get the state of minimum... 

When we were looking at the electronic configuration of atoms, we simply filled up the atomic orbitals starting from the lowest in energy and worked up. With molecules we do the same we just fill up the molecular orbitals with however many electrons we have, starting from the lowest in energy and remembering that each orbital can hold two electrons and then only if they are spin paired. 

Electron configurations of atoms can now be written by making use of the maximum occupancy and the order of filling the orbitals. The state of lowest energy is the ground state, and the electron configurations for all elements are shown in Appendix A. The filling... 

Hybridization can also help explain the existence and structure of many inorganic molecular ions. Consider, for example, the zinc compounds shown here. At the top is shown the electron configuration of atomic zinc, and just below it, of the divalent zinc ion. Notice that this ion has no electrons at all in its 4-shell. In zinc chloride, shown in the third row, there are two equivalent chlorine atoms bonded to the zinc. The bonding orbitals are of sp character that is, they are hybrids of the 4s and one 4p orbital of the zinc atom. Since these orbitals are empty in the isolated zinc ion, the bonding electrons themselves are all contributed by the chlorine atoms, or rather, the chlor ide ions, for it is these that are the bonded species here. Each chloride ion possesses a complete octet of electrons, and two of these electrons occupy each sp bond orbital in the zinc chloride complex ion. This is an example of a coordinate covalent bond, in which the bonded atom contributes both of the electrons that make up the shared pair. 

Predict the ground state electronic configuration of atoms. 

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