How can properties of an element be predicted

If the valence shell of an atom is less than half full, it requires less energy to lose an electron than to gain one. Conversely, if the valence shell is more than half full, it is easier to pull an electron into the valence shell than to donate one.

From top to bottom down a group, electronegativity decreases. This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius. Important exceptions of the above rules include the noble gases, lanthanides , and actinides.

The noble gases possess a complete valence shell and do not usually attract electrons. The lanthanides and actinides possess more complicated chemistry that does not generally follow any trends. Therefore, noble gases, lanthanides, and actinides do not have electronegativity values.

As for the transition metals, although they have electronegativity values, there is little variance among them across the period and up and down a group. This is because their metallic properties affect their ability to attract electrons as easily as the other elements.

Ionization Energy Trends Ionization energy is the energy required to remove an electron from a neutral atom in its gaseous phase. Trends The ionization energy of the elements within a period generally increases from left to right. This is due to valence shell stability. The ionization energy of the elements within a group generally decreases from top to bottom. This is due to electron shielding. The noble gases possess very high ionization energies because of their full valence shells as indicated in the graph.

Note that helium has the highest ionization energy of all the elements. Electron Affinity Trends As the name suggests, electron affinity is the ability of an atom to accept an electron. Electron affinity increases from left to right within a period. This is caused by the decrease in atomic radius. Electron affinity decreases from top to bottom within a group.

This is caused by the increase in atomic radius. Atomic Radius Trends The atomic radius is one-half the distance between the nuclei of two atoms just like a radius is half the diameter of a circle.

Atomic radius decreases from left to right within a period. This is caused by the increase in the number of protons and electrons across a period. One proton has a greater effect than one electron; thus, electrons are pulled towards the nucleus, resulting in a smaller radius. Atomic radius increases from top to bottom within a group.

This is caused by electron shielding. Melting Point Trends The melting points is the amount of energy required to break a bond s to change the solid phase of a substance to a liquid. Metals generally possess a high melting point.

Most non-metals possess low melting points. The non-metal carbon possesses the highest melting point of all the elements. The semi-metal boron also possesses a high melting point. Metallic Character Trends The metallic character of an element can be defined as how readily an atom can lose an electron.

Metallic characteristics decrease from left to right across a period. This is caused by the decrease in radius caused by Z eff , as stated above of the atom that allows the outer electrons to ionize more readily. Metallic characteristics increase down a group.

Electron shielding causes the atomic radius to increase thus the outer electrons ionizes more readily than electrons in smaller atoms. Metallic character relates to the ability to lose electrons, and nonmetallic character relates to the ability to gain electrons. Problems The following series of problems reviews general understanding of the aforementioned material. Nitrogen has a larger atomic radius than oxygen.

True B. False 3. Which has more metallic character, Lead Pb or Tin Sn? Which element has a higher melting point: chlorine Cl or bromine Br? Which element is more electronegative, sulfur S or selenium Se? Oxygen O B. Chlorine Cl C. Calcium Ca D. Lithium Li E. None of the above 10 A nonmetal has a smaller ionic radius compared with a metal of the same period. Solutions 1. References Pinto, Gabriel. Iqbal M. Smith, Derek W. Group and Electron Configuration The group column of the periodic table determines the valence electron count.

Metal and Non-metal The periodic table is divided into metals on the left and non-metals on the right. Electronegativity Electronegativity is the tendency of an element to attract electrons.

I hope this was helpful. Related questions What periodic table elements are radioactive? How can the periodic table be used to predict the properties of the elements? How can elements have different isotopes? How can elements be broken down? What is a chemical element? What element in the fourth period of the periodic table has 5 valence electrons? The p-block elements are found on the right side of the periodic table. They include the boron, carbon, nitrogen, oxygen and flourine families in addition to the noble gases.

The s-block and p-block elements are so called because their valence electrons are in an s orbital or p orbital respectively. They are also called Typical Elements to distinguish them from the transition and inner transition series. The s-block in the periodic table of elements occupies the alkali metals and alkaline earth metals, also known as groups 1 and 2.

Helium is also part of the s block. There is a maximum of two electrons that can occupy the s orbital. Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Physics Which property Cannot be predicted for an element based on its location in the periodic table?