Are you a chemistry student? Visit A-Level Chemistry to download comprehensive revision materials - for UK or international students!

Metallic Bond

Metallic Bond Definition Metallic bonding is a special type of bonding that holds the metals together in metal crystal. This bond is neither covalent nor ionic. Metals have tendency to give up electrons and none is their to accept it. There are several theories to explain this type of bonding, among them the electron sea … Read more

Atomic radius

Definition of atomic radius The atomic radius is the size of the atom, typically measured by the distance from the nucleus of the atom to the electron clouds around the nucleus. As there are no physical existence of orbital in atoms, it is difficult to measure the atomic radius. Thus sometime different methods are used … Read more

Electron affinity

Definition of electron affinity Electron affinity is the affinity of an element to an electron. This is measured by the energy released when an element in its gaseous state accepts an electron to form an anion. So this is an exothermic reaction. They are expressed in KJ mol-1. M(g) + e– → M–(g)       EA Since … Read more

Hydrogen Bond

Hydrogen Bond Definition Hydrogen bond is an attractive force between a partially positive charged hydrogen and a partially negative charged atom (oxygen and nitrogen). This is a very weak bond and strength of hydrogen bond (5-10 Kcal per bond) is much less than the strength of covalent bond. Hydrogen bonds are usually showed as dotted … Read more

Ionization Energy

Ionization Energy Definition The ionization energy (IE) or ionization potential is the energy needed to remove an electron from an atom in the gaseous state. M(g) → M+(g) + e–      IE Since one, two or more electrons can be removed from an atom, many ionization energy is possible of that atom. The first ionization energy (IE1) … Read more

Covalent Bond

Covalent Bond Definition A covalent bond is a chemical bond that involves the sharing of electron pairs between two atoms. These electron pairs are known as bonding electron pairs, and they share these electrons to form covalent bond. This bonding is  primarily found between nonmetals; however, it can also be observed between nonmetals and metals. Covalent Bond Example … Read more


Electronegativity Definition Electronegativity is a chemical property that measures the tendency of an atom to attract electrons towards itself. Electronegativity is affected by the atomic number and the distance between the valence electrons and its nucleus. The higher the electronegativity is the more it attracts the electrons towards it. Types of Electronegativity Non Polar Bond … Read more