Noble Gases: A Chemical Family
For Mrs. O'Toole's Honors Chemistry Class
Location on the Periodic Table4
This book is all about the farthest right column of the Periodic Table: the Noble Gases. The elements that classify as Noble Gases are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn). As their name implies, they are all gases at room temperature. The Noble Gases are special because their outer shell has the maximum number of electrons allowed in it. Because of this, they are mostly unreactive. You may see the Noble Gases be refered to as the "Inert Gases." The word "inert' means "inactive."
The Noble Gases are located in the column the farthest to the right on the Periodic Table. This is also called Group 8A, 18 or even Group Zero! With the exception of Helium which has 2, all of the Noble Gases have eight valence electrons. This means they would not have to gain or lose any electrons to become stable because they already are, so their valence number would be zero. Lastly, if you go across the Periodic Table counting each column, the Noble Gases would be the 18th one you count.
Since atomic radius decreases from left to right, and the Noble Gases are farthest to the right, they have a low atmoic radius. As you go down the family, the atomic radius increases. The Noble Gas with the highest atomic radius would be Radon.
Since Noble Gases have a full octet, they don't form ions. Because of this, Noble Gases don't have an ionic radius
Ionization energy is the amount of energy required to remove the most loosely held electron. Since Noble Gases have a full outer shell, it would take a lot of energy to rip an electron from it. Noble Gases have high ionization energy, and Helium has the highest ionization energy.
Electronegativity is the ability of an element to gain an electron in a bonding situation. As mentioned earlier, Noble Gases already have a full octet, so they don't need to attract any more electrons. Therefore, Noble Gases don't have electronegativity either!
Noble Gases have a very low reactivity with other elements. This is again due to the fact that they have a full octet, making them stable.
atomic radius- the distance from the nucleus to the farthest occupied energy level
element family- the elements in one vertical column on the Periodic table that have similar properties
full octet- when an element has the maximum amount of electrons in its highest energy level. This number is usually 8, except for Helium, which has 2.
ion- an atom where the total number of electrons differ from the total number of protons
ionic radius- the dsitance from the nuclues to the farthest occupied energy level of the most commonly formed ion
valence number/electrons- another name for the number of electrons in an element's highest energy level