Quantum Numbers

Thursday and Friday in class we learned about quantum numbers and electron configurations!
The three coordinates that come from Schrödinger's wave equations are the principal (n), angular (l), and magnetic (m) quantum numbers. These quantum numbers describe the size, shape, and orientation in space of the orbitals on an atom.
The principal quantum number (n) describes the size of the orbital. Orbitals for which n = 2 are larger than those for which n = 1, for example. Because they have opposite electrical charges, electrons are attracted to the nucleus of the atom. Energy must therefore be absorbed to excite an electron from an orbital in which the electron is close to the nucleus (n = 1) into an orbital in which it is further from the nucleus (n = 2). The principal quantum number therefore indirectly describes the energy of an orbital.
The angular quantum number (l) describes the shape of the orbital. Orbitals have shapes that are best described as spherical (l = 0), polar (l = 1), or cloverleaf (l = 2). They can even take on more complex shapes as the value of the angular quantum number becomes larger.
There is only one way in which a sphere (l = 0) can be oriented in space. Orbitals that have polar (l = 1) or cloverleaf (l = 2) shapes, however, can point in different directions.
3) We therefore need a third quantum number, known as the magnetic quantum number (m), to describe the orientation in space of a particular orbital. (It is called the magnetic quantum number because the effect of different orientations of orbitals was first observed in the presence of a magnetic field.)

Rules Governing the Allowed Combinations of Quantum Numbers

• The three quantum numbers (n, l, and m) that describe an orbital are integers: 0, 1, 2, 3, and so on.
• The principal quantum number (n) cannot be zero. The allowed values of n are therefore 1, 2, 3, 4, and so on.
• The angular quantum number (l) can be any integer between 0 and n - 1. If n = 3, for example, l can be either 0, 1, or 2.
• The magnetic quantum number (m) can be any integer between -l and +l. If l = 2, m can be either -2, -1, 0, +1, or +2.

CONFIGURATION CHART

The next scribe is Jeff M.

Acids

Today in Class We...

1. Got Quiz 2.1 back
2. Went over acids and naming them
3. Reviewed naming Ionic and Covalent compounds
4. Took Quiz over naming Ionic and Covalent compounds

Acids

Acids are substances formed when nonmetal ions combine with hydrogen. The hydrogen is written first in the compound and the naming is based on whether the anion (negative ion) is:

• simple
• polyatomic.

When acids ionize they form H+ ions.

• Acids always contain hydrogen.
• Example: Hydrogen and Chlorine:

               -HCl or Hydrochloric acid

Naming Acids                            *Trick to remember Acids: 'ate'ic- 'ite'is

If an anion does not contain oxygen-            

• change the ending to "ic"                                                                                        
• add prefix hydro
• HF Hydrofluoric acid

If an anion does contain oxygen

• "ate" becomes "ic"                                
• "ite" becomes "ous"

Examples:  -H₃PO₄ - anion is phosphate = phosphoric acid
                    -HCN- hydrogen + cyanide = hydrocyanic acid
                    -H₂SO₃ - anion is sulfite = sulfurous acid

 Homework for tonight:

• Naming Workshop worksheet
• Study for naming quiz tomorrow *8 polyatomic ions need to be memorized

The next scribe will be Kevin L.