Stability and Ionic Bonding. Section 20.1 & 20.2. SC Standards Covered. Standard PS-4.1 Explain the role of bonding in achieving chemical stability. Standard PS-2.5
Section 20.1 & 20.2
Why do Elements Form Compounds?
- the noble gases are extremely stable atoms that do not combine with other elements.
- it is the eight valence electrons that make the noble gas atoms stable
What ion will Sodium form?
Since sodium has 1 valence electron it can lose that electron and then have eight valence elect.
Superscript – written above line; gives the charge of ion
Group 1 → 1 valence e- → +1
Group 2 → 2 valence e- → +2
Group 13 → 3 valence e- → +3
Fluorine needs to gain 1e- in order to become stable
- This will give fluorine a -1 charge
Group 17 → 7 valence e-→ -1
Group 16 → 6 valence e- → -2
Group 15 → 5 valence e- → -3
Explain the formation of the ionic bond between sodium and chlorine
Na+[ Cl ]-1
Electron dot struct.
5. Write out the chemical formula using subscripts to show how many of each element it took
[ O ]-2
Use electron dot structures to write chemical formulas for the following combination of elements: