classifying compounds

Classifying compounds

Compounds are classified by the number of elements they contain

  • binary compounds: two different elements

  • ternary compounds: three different elements

Covalent molecular compounds

  • involves the joining of two nonmetals

  • atoms are held together by covalent bonds

  • it's the sharing of electrons

  • solid liquid or gas at room temperature

Ionic compound

  • involves the joining of a nonmetal and a metal

  • atoms are held together by ionic bonds

  • it's the transfering of electrons

  • solid at room temperature


 molecular/covalent compounds

  •  a combination of at least two atoms in a specific Arrangement held together by a covalent chemical bond

Examples: be diatomic and polyatomic

  • Diatomic molecules: consist of two atoms

    • Homonuclear: two of the same atoms

      • There are seven elements that exist as a diatomic molecule

        • hydrogen (H2), nitrogen (N2), fluorine (F2), oxygen (O2), iodine (I2), chlorine (Cl2) and bromine (Br2).

    • heteronuclear: two different atoms

      • Examples: CO, HF

  • Polyatomic molecules 

    • Contain more than two atoms 

    • most molecules

    • may contain more than one element 

      • examples: O3, H2O, CH4, P4, C8, N4O2

Molecular formula: shows the exact number of atoms of each element in a molecule

  • The subscript indicates the number of atoms of each element present in the formula.

  • H2O contains 2 atoms of hydrogen and 1 atom of oxygen

  • Examples: C2H60, C02, C8H10N402




Naming covalent/molecular compounds 

You must use prefixes and numbers to refer to the right chemical compounds.

Steps: 

  1. Write the name of the two elements in the order they're listed in the formula

  2.  use prefixes to represent the amount of each atom

    1.  if just one atom of the first element is present, do not use mono

    2.  vowels at the end of the prefix are sometimes dropped when the atoms start with a vowel

  3.  and the name of the second element with “ide.”