1. a chemical bond formed by the electrostatic attraction between ions covalent bond

2. a chemical bond formed by two electrons that are shared between two atoms energy level

3. the orbitals of an atom where electrons are found ionic bond

4. the smallest particle of a covalently bonded substance metallic bond

5. a bond characteristic of metals in which mobile valence electrons are shared among positive nuclei in the metallic crystal molecule

When there occurs sharing of electrons between two chemically combining atoms then it forms a covalent bond. Generally, a covalent bond is formed between two non-metals.

An ionic bond is defined as the bond formed due to transfer of one or more number of electrons from one atom to another. An ionic bond is always formed between a metal and a non-metal.

Every atom of an element will have orbitals in which electrons are found. These orbitals are known as energy level.

A molecule is defined as the smallest particle present in a substance or atom.

A metallic bond is formed due to mobile valence electrons shared by positive nuclei in a metallic crystal.

Thus, we can conclude that given statements are correctly matched as follows.

1). a chemical bond formed by the electrostatic attraction between ions - ionic bond

2). a chemical bond formed by two electrons that are shared between two atoms - covalent bond

3). the orbitals of an atom where electrons are found - energy level

4). the smallest particle of a covalently bonded substance - molecule

5). a bond characteristic of metals in which mobile valence electrons are shared among positive nuclei in the metallic crystal - metallic bond