Chapter One Flashcards
Why is structure important?
It determines the function of a molecule
What is the atomic number
the number of protons
What is the mass number
The protons + the neutrons
What are isotopes?
same atomic numbers with a different atomic mass
What is the atomic mass representative of?
The average mass of elements’ naturally occurring isotopes
What the formal charge formula
formal charge = #valence electrons -1/2(shared electrons) - (#unshared electrons)
How many bonds does a neutral hydrogen like?
1
How many covalent bonds does a neutral carbon like?
4
how many bonds does a neutral nitrogen like
3 or 4
how many bonds does oxygen like
2 (divalent)
how many bonds do Halogen like?
1 (monovalent)
What is the Aufbau principle?
Start filling the electron orbitals from the lowest up
What is the poly-exclusion principle?
only 2 electrons can fill an orbital with different spins
What is Hund’s rule?
if empty orbitals of equal energy are available, one electron occupies each with parallel spins
What is valence bond theory?
A covalent bond forms when 2 atoms approach each other closely so that one singly occupied orbital on one atom overlaps with another singley occupied orbital
When a bond is formed
energy is lost as the energy level becomes lower, making it exothermic
When a bond is broken
Energy is absorbed
what are isomers
different compounds with the same molecular formula
what are constitutional isomers?
compounds with different structures but the same formula
what are the rules of resonance
resonance forms are imaginary but hybrids are real
only the electrons move
only proper lewis structure forms can exist (octet rule)
resonance hybrids are the most stable due to their de localized charge)
what is an electron group
lone pairs, single/double/triple bonds
how many electron groups does s hybrid need
1
how many e groups does sp hybrid need
2
how many e groups does sp2 hybrid need
3
