How does electron configuration relate to the periodic table

Number of electrons in outermost shell. Group number. Total number of electrons in all shells. Atomic number. Their electron configurations abbreviated for the larger atoms are as follows, with the valence shell electron configuration highlighted:. They all have a similar electron configuration in their valence shells: a single s electron.

Because much of the chemistry of an element is influenced by valence electrons, we would expect that these elements would have similar chemistry— and they do. The organization of electrons in atoms explains not only the shape of the periodic table, but also the fact that elements in the same column of the periodic table have similar chemistry. The same concept applies to the other columns of the periodic table. Elements in each column have the same valence shell electron configurations, and the elements have some similar chemical properties.

This is strictly true for all elements in the s and p blocks. In the d and f blocks, because there are exceptions to the order of filling of subshells with electrons, similar valence shells are not absolute in these blocks. However, many similarities do exist in these blocks, so a similarity in chemical properties is expected.

Similarity of valence shell electron configuration implies that we can determine the electron configuration of an atom solely by its position on the periodic table. They also tend to have similar properties.

So if you do electron configuration with column 2 of periodic table you will also get 2 valance eleectrons in s orbital for Mg and Ca etc. How does electron configuration relate to the periodic table?

Chemistry Electron Configuration Electron Configuration. Pimolrat M. Carbon dioxide is notable because it is a case in which two pairs of electrons four in all are shared by the same two atoms.

This is an example of a double covalent bond. Non-bonding valence electrons are shown as dots. These formulas are derived from the graphic notations suggested by A. Couper and A. Some examples of such structural formulas are given in the following table. Multiple bonding , the sharing of two or more electron pairs, is illustrated by ethylene and formaldehyde each has a double bond , and acetylene and hydrogen cyanide each with a triple bond.

Boron compounds such as BH 3 and BF 3 are exceptional in that conventional covalent bonding does not expand the valence shell occupancy of boron to an octet. Consequently, these compounds have an affinity for electrons, and they exhibit exceptional reactivity when compared with the compounds shown above. The number of valence shell electrons an atom must gain or lose to achieve a valence octet is called valence. In covalent compounds the number of bonds which are characteristically formed by a given atom is equal to that atom's valence.

From the formulas written above, we arrive at the following general valence assignments:. The valences noted here represent the most common form these elements assume in organic compounds. Many elements, such as chlorine, bromine and iodine, are known to exist in several valence states in different inorganic compounds.

Charge Distribution. If the electron pairs in covalent bonds were donated and shared absolutely evenly there would be no fixed local charges within a molecule. A dipole exists when the centers of positive and negative charge distribution do not coincide.

A large local charge separation usually results when a shared electron pair is donated unilaterally. In the formula for ozone the central oxygen atom has three bonds and a full positive charge while the right hand oxygen has a single bond and is negatively charged. The overall charge of the ozone molecule is therefore zero. Similarly, nitromethane has a positive-charged nitrogen and a negative-charged oxygen, the total molecular charge again being zero.

Finally, azide anion has two negative-charged nitrogens and one positive-charged nitrogen, the total charge being minus one. In general, for covalently bonded atoms having valence shell electron octets , if the number of covalent bonds to an atom is greater than its normal valence it will carry a positive charge. If the number of covalent bonds to an atom is less than its normal valence it will carry a negative charge.

The formal charge on an atom may also be calculated by the following formula:. The ability of an element to attract or hold onto electrons is called electronegativity. A rough quantitative scale of electronegativity values was established by Linus Pauling , and some of these are given in the table to the right.