chem chapter 8 Flashcards
valance electrons of an atom for main group elements
s and p electrons with highest value of n
ex: carbon: 1s2 2s2 2p2, valence =2s2 2p2=4 (counting the exponents)
the core electrons are the ones not included
valance electrons for transition metals
s and d electrons with the highest value of n
ex) Titanium: [Ar] 4s2 3d2, valance =4
the core electrons are the ones not included
chemical reactions with core and valance electrons
-core: not participating in the chemical reaction or bonds (ignore them)
-valance electrons: chemical reactions result in the loss, gain, or rearrangement of valance electrons
atoms tend to ionize until they achieve…
the valance electron configuration of a noble gas (ns2 np6)
they will bond to achieve this
covalent compound
nonmetal + nonmetal
electrons SHARED through bonds
ionic compound
metal + nonmetal
electrons are TRANSFERRED and electrostatic forces keep the ions together
octet rule
atoms want to have 8 valance electrons and will bond to get there
lewis symbols of ions
have either 8 valance electrons or none
cations with lewis symbols
take away the electrons to make a positive charge
anions with lewis symbols
add electrons to equal a negative charge
when does a chemical reaction occur?
when two atoms have some of their valance electrons reorganized resulting in a net attractive force between the atoms (a chemical bond)
bonding pair
the SHARED electrons in covalent compounds
pure covalent compound
occurs when two identical atoms are bonded
ex) H + H goes to H2
what happens when two different atoms form a covalent compound?
the electrons are shared unequally
the bonding electrons will be closer to the more electronegative atom
polar covalent bond
bonding of two different atoms in a covalent compound
one atom has a partial negative charge and the other has a partial negative charge
(because the electrons will move to the more electronegative atom)
