chapter 1 part 1 Flashcards
why is carbon important or nature
carbon forms strong bonds to other carbons and can form rings/chains of carbons; carbon also forms strong bonds to hydrogen, nitrogen, oxygen and sulfur
atomic number
number of protons in the nucleus
isotopes
same number of protons but different mass because of the different numbers of neutrons
number of valence
equal to the group number of the atom
carbon
4 valence electrond
nitrogen
5 valence electrons
halogens
7 valence electrons
ionic bonds
formed by electron transfer btw atoms and can create ions (an attractive force between oppositely charged ions)
covalent bonds
shared electrons btw atoms of similar electronegativities (in molecules)
ions
particles created by ionic bonds or by the gaining and loss of electrons (may contain covalent bonds)
octet rule
followed by the 2nd row because they have one 2s and three 2p orbitals but always followed by the 3rd row because they have d orbitals
formal charge
number of valence electrons- half the number of shared electrons- number of unshared electrons
isomers
different compounds that have the same molecular fomrula
constitutional isomers
same molecular formula but different connectivity (atoms connected in a different order)
dashed wedge
bond that lies behind the place
solid wedge
bond the lies in front of place
regular line
bond that is on the plane of the paper (2d)
resonance theory
two or more lewis structures are needed; happens when more than one lewis structure can represent the same molecule; they are different only in the positions of electrons and are not real structures
resonance stabilization
the real structure is the hybrid; it has lower energy than the contributing structures and are therefore more stable (more equivalent resonance structures mean more stabalization)
curved arrows
show the flow of electrons from higher electrons density to lower electron density
hybrid
the more covalent bonds the structure has the more stable it is, a complete valence shell is also more stable
carbon with a positive charge
will only make 3 bonds because it only has 3 valence electrons (will affect the number of hydrogens attached)
carbon with a negative charge
has 5 valence (has lone pair) (carbon c an NEVER make 5 bonds) (can only form 3 bonds) (will also affect hydrogens present)
positive charge
missing electrons