Final answer:
Oxygen (O₂) forms covalent bonds, sodium fluoride (NaF) and potassium chloride (KCl) both form ionic bonds, methane (CH₄) is covalently bonded, and iron (Fe) displays metallic bonding.
Step-by-step explanation:
Types of Chemical Bonds
Classifying substances by their type of bond — ionic, covalent, or metallic — involves looking at the elements that make up these substances and considering their average electronegativity (AvgEN) and the difference in electronegativity (∆EN) between them. For the substances provided:
- O₂ has a covalent bond as it is a diatomic molecule composed of two oxygen atoms sharing electrons equally.
- NaF exhibits ionic bonding since sodium (metal) transfers its electron to fluorine (non-metal), resulting in an electrostatic attraction between the oppositely charged ions.
- KCl is another example of ionic bonding due to the metal potassium transferring its electron to the non-metal chlorine.
- CH₄ (methane) has covalent bonding as it consists of carbon and hydrogen atoms sharing electrons.
- Fe (iron) is a metal, hence it displays metallic bonding, which involves a 'sea of electrons' that are delocalized over a lattice of metal cations.
It is important to identify these bonds correctly to understand the chemical and physical properties of these substances such as electrical conductivity, melting and boiling points, solubility, and reactivity. The types of chemical bonds are crucial for the formation and stability of compounds with distinct characteristics.