Shapes and Bonds Flashcards
What is the range of EN for non-polar cov. bonds?
0 - 0.4
What is the range of EN for polar cov. bonds?
0.4 to 1.7
What is the range of EN for ionic bonds?
1.7+
What is the octet rule?
most elements need 8 electrons to be stable
Exceptions to the octet rule
H = 2e
Be = 4e
B = 6e
S + P sometimes have more than 8
What is an expanded octet?
When the central atom has extra pairs of electrons beyond 4
What do you ask yourself to determine if a structure shows resonance?
Do I have any double bonds? Can the double bond be moved to other locations?
How do you indicate the pull/polarity of a bond?
Label each element with EN value.
Draw an arrow above bonds pointing to the element with the more EN
Place a -delta towards the more EN, +delta away
High Melting/Boiling Point, Soluble in Water, Conducts Electricity in Molten & Aqueous State
Ionic
High Melt/Boil Point, Conducts electricity in solid & molten state, has luster
metallic
low melt/boil point, not soluble in water, doesn’t conduct electricity
non-polar covalent
medium melting/boil point (higher than non-polar, lower than ionic), soluble in water (but not in non-polar solvents), doesn’t conduct electricity, liquid at room temp, exists as a molecule not ions
polar covalent
Which compounds contain both ionic and compound bonds?
polyatomics
What does it mean for an element to be considered diatomic?
has 2 bonded atoms, covalent, both with same EN
List the diatomic elements
Br, Cl, F, O, N, H
