Physical Science Week 11
Day 1 | Day 2 - 3 | Lab | Vocabulary Test | Atoms WebQuiz

Octet Rule Quantum numbers	Energy level Sublevel Orbital	Electron spin Electron configuration

Why don't the Noble Gases form compounds?

The Octet Rule: The maximum number of electrons in the outer electron energy level of an atom is eight. Atoms are most stable when they have eight electrons in their outer electron energy level.

The 4 Quantum Numbers:

n - represents the electron energy level.

• 1 to 7
• The 7 horizontal rows on the Periodic Table represent the energy levels.
• Maximum number of electrons = 2n²

l - represents the electron energy sublevel.

• s - p - d - f
• The two columns on the left of the table represent the s sublevel.
• The six columns on the right of the table represent the p sublevel.
  • Notice that He is moved beside H.
• The ten columns in the middle of the table represent the d sublevel.
• The fourteen columns of two below the table represent the f sublevel.

m - represents the orbital within the sublevel.

• An orbital contains no more than two electrons.
• s has 1 orbital
• p has 3 orbitals
• d has 5 orbitals
• f has 7 orbitals

s - represents the spin of the electron.

• Clockwise
• Counter clockwise
• Electrons in the same orbital must have opposite spins.

Computer Assignment 111:
This assignment must be completed by the beginning of class tomorrow to receive credit.
Scoring criteria

1. Paste this periodic table onto a PowerPoint slide.
   1. Cover the area on the table that represents the s sublevels with a "semi-transparent" green rectangle. Type an "s" in the middle of this rectangle using large yellow font with black shadow.
   2. Cover the area on the table that represents the p sublevels with a "semi-transparent" red rectangle. Type a "p" in the middle of this rectangle using large blue font with black shadow.
   3. Cover the area on the table that represents the d sublevels with a bright yellow rectangle. Type a "d" in the middle of this rectangle using large red font with black shadow.
   4. Cover the area on the table that represents the f sublevels with a "semi-transparent" blue rectangle. Type an "f" in the middle of this rectangle using large white font with black shadow.

   Save this PowerPoint file on your computer and show it to your science facilitator.

Physical Science Week 11 - Day 2 - 3

Reading electron configuration directly from the Periodic Table:

Think of each element box on the Periodic Table as an electron.
Count and name the electrons on the table reading from left to right.
Only three adjustments must be made:
1. Helium is directly next to hydrogen, putting it in the s sublevel, not the p.
2. Because of energy overlaps, the first d sublevel is 3rd, not 4th electron energy level.
3. Because of energy overlaps, the first f sublevel is 4th, not 6th electron energy level.

There are two ways to check this electron configuration: The total of all exponents should equal the atomic number of the atom. The large number and small-case letter represent the electron energy level and sublevel The exponent number represents the number of electrons in that sublevel Is the exponent total equal to the atomic number of calcium? Look at the last part of the electron configuration, in this case 4s2, find this square on the periodic table - it should be the element represented by the electron configuration. Is the second square in the s sublevel of energy level 4 calcium?

Here are four more examples of electron configurations: Carbon - 1s2 2s2 2p2 Carbon's atomic number (number of electrons) is 6. Carbon is the second square in the p sublevel of the second energy level. Aluminum - 1s2 2s2 2p6 3s2 3p1 Aluminum's atomic number (number of electrons) is 13. Aluminum is the first square in the p sublevel of the third energy level. Nickel - 1s2 2s2 2p6 3s2 3p6 4s2 3d8 Nickel's atomic number (number of electrons) is 28. Nickel is the eighth square in the d sublevel of the third energy level. Bromine - 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 Bromine's atomic number (number of electrons) is 35. Bromine is the fifth square in the p sublevel of the fourth energy level.

Forensic Scientist

In-class Assignment 113:
This assignment must be turned in by the end of class today to receive credit.
Scoring criteria

1. Write the complete electron configuration for the following atoms:
   1. magnesium
   2. zinc
   3. strontium
   4. silver
   5. tin

Physical Science

Electron Configuration Answers

1. magnesium - 1s² 2s² 2p⁶ 3s²

2. zinc - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰

3. strontium - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²

4. silver - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁹

5. tin - 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p²

The Nobel Gases don't form compounds because their outer electron energy level has eight electrons.
Atoms form compounds to fill their outer energy level with eight electrons. Since the Nobel Gases already have that, they are chemically stable.

The letters in an electron configuration represent electron energy sublevels.