Lab Report On Diatomic Molecules

Description

Did you know that diatomic molecules make up majority of the Earth’s atmosphere? The prefix “di” means ‘’two’’ in Greek, so these diatomic molecules are made up of two atoms. In this lesson, we will discuss diatomic molecules and go over some examples.

!!!What is a Diatomic Molecule?

Diatomic molecules are all around us. The Earth’s atmosphere is mainly composed of about 78% oxygen and 21% nitrogen. The oxygen and nitrogen present in the atmosphere are both in the form of ‘’diatomic molecules’’, as shown below:

The subscript 2 of oxygen and nitrogen indicate the number of oxygen atoms and nitrogen atoms. So the oxygen molecules present in the atmosphere have two oxygen atoms and the nitrogen molecules have two nitrogen atoms.
Carbon monoxide (CO) is produced from combustion fumes of cars and trucks, and is made of one carbon (C) atom and one oxygen (O) atom. Hydrochloric acid (HCl) is present in the gastric acid produced by our stomach, and is a common acid that we use in the chemistry lab. It is made of one hydrogen (H) atom and one chlorine (Cl) atom:

__Diatomic molecules__ are molecules that are composed only of ‘’two atoms’’. Diatomic molecules are either ‘’homonuclear’’ or ‘’heteronuclear’’. __Homonuclear diatomic molecules__ are composed of two atoms of the ‘’same element’’, like in the case of oxygen (O2) and nitrogen (N2) shown in the illustration above. __Heteronuclear diatomic molecules__ are composed of two atoms of ‘’different elements’’, like in the case of hydrochloric acid (HCl) and carbon monoxide (CO).

The two atoms in a diatomic molecule are connected in a straight line. The __molecular geometry__, which is what describes the shape, of a diatomic molecule is a ‘’linear geometry’’. Shown below are the __Lewis structures__, which show how atoms are bonded in the molecule and lone pairs of electrons, of the diatomic molecules O2, N2, HCl and CO. The red dots represent the electrons and the lines represent the bonds. We can see here that the diatomic molecules exhibit linear molecular
The lanthanides and actinides are also classified as metals.

The following are examples of heteronuclear diatomic molecules with ionic bonding:

Let us take NaCl, for example, sodium (Na) is on the far left side of the periodic table, indicating it is a metal, and chlorine (Cl) is a nonmetal, so NaCl is a heteronuclear diatomic molecule with an ionic bond.

The following are examples of heteronuclear diatomic molecules with covalent bonding:

Let us look at HBr, for example. Hydrogen is on the left side of the stairs that divide metals and nonmetals in the periodic table, but ‘’hydrogen is a nonmetal’’. Bromine (Br) is also a nonmetal, so HBr is a heteronuclear diatomic molecule with a covalent bond.

!!!Lesson Summary

__Diatomic molecules__ consist of two atoms that are either from the same element, or from different elements. If the diatomic molecule consists of atoms of the same element, then this is classified as a __homonuclear diatomic molecule__. If the diatomic molecule consists of atoms from two different elements, then it is a __heteronuclear diatomic