Atoms gain or lose electrons based on their respective electron affinity. The greater the electron affinity of an atom, the more likely that atom is to accept an electron. Electron affinity changes based on the group of elements to which an atom belongs.Know More
There are several factors that affect the electron affinity of an atom. The effective nuclear charge is the positive charge exhibited by the protons in the nucleus of an atom. The greater the effective nuclear charge of an atom, the greater its electron affinity. Because effective nuclear charge becomes stronger when traveling from right to left on the periodic table of elements, the electron affinity across a period exhibits a similar trend. Electron affinity generally follows the same increasing and decreasing trends across a periodic table as electronegativity, and one can be used to estimate the other when comparing two atoms of different elements.
The number of electrons required to fill the outermost electron shell also affects the electron affinity of an atom. Halogens such as chlorine and iodine require only one electron to have all their electron shells completely filled, and they have a strong electron affinity. Noble gases already have completely filled electron shells and do not require additional electrons for stability, giving them a very low electron affinity.Learn more about Atoms & Molecules
In a polar covalent bond, the electrons are shared unevenly between the two bonded atoms. This means that the electrons, which are constantly moving, spend more time with the one atom than the other. Only the outer most electrons, known as valence electrons, are involved in polar covalent bonds.Full Answer >
Metals have the tendency to lose electrons. The type of chemical bonding formed by atoms of metallic elements is called metallic bonding.Full Answer >
Covalent bonds form when atoms share their valence electrons with other atoms to become a more stable molecule. Atoms share their electrons in order to completely fill up their outer-most layer — the valence shell. Two atoms that are covalently bonded have less energy than the individual atoms, making the bonded atoms more stable.Full Answer >
Metals are the only substances that use metallic bonds among their atoms. While many elements are commonly known as metals, including iron, aluminum, gold, silver and nickel, metals include a variety of other elements as well. Most elements are metals, including some such as sodium, radium and calcium, which may not seem very metallic.Full Answer >