An atom's reactivity is determined by the number of electrons in its outermost shell. Because the outer shell can hold up to eight electrons and not all elements are able to fill these shells to capacity, the fullness of the shells will determine the volatility of the atom's reactive properties as a result of the number of electrons required to complete the shell.
Atoms with low reactivity have full atom shells. The noble gases, including neon, argon and krypton, fall into this category, as they are atoms that naturally present with full electron shells and are not looking to gain or lose electrons to achieve a balanced outer shell.
Atoms with high reactivity have outer shells that are imbalanced because of a low number of electrons (one or two) or a higher but not full number (six or seven). The most highly reactive elements are halogens, which are looking to gain one more electron, and alkali metals, which are looking to lose the single electron in their outer shells.Learn More
Iron rusts when it comes in contact with oxygen and water. It rusts faster in acid rain and salty water. Both oxygen and water are necessary for rusting, which is an oxidation reaction.Full Answer >
Aluminum reacts with oxygen to form a layer of aluminum oxide on the outside of the metal, according to HowStuffWorks. This thin layer protects the underlying metal from corrosion caused by oxygen, water or other chemicals. Aluminum burns in oxygen with a white flame to form the trioxide aluminum (III) oxide, says WebElements. Chemists write the chemical reaction between aluminum and oxygen as: 4Al+ 3O2 = 2Al2O3.Full Answer >
Boron was discovered in 1808. French chemists Joseph-Louis Gay-Lussac and Louis-Jaques Thénard and English chemist Sir Humphry Davy independently isolated the element, and all three are credited with its discovery.Full Answer >
Noble gases are inert due to their complete electron shells. Their stable atomic structure makes the energy required to add or remove an electron prohibitively high, so the noble gases do not form compounds in natural conditions.Full Answer >