chemical bonding Flashcards
(40 cards)
what are the 3 general ways atoms join together
ionic
covalent
metallic
what is the purpose of a pew dot diagram
to show the valence electrons of an atom
what is ionic bonding
non metal bonds with a metal (takes electrons) so all atoms end up with 8 valence electrons
what is covalent bonding
non metal bonds with a non metal so all atoms end up with 8 valence electrons
what is metallic bonding
two metals that bonded, positive ion in a sea of electrons
which is the weakest bond
metallic
what is an ion
any atom with more or less electrons than it is supposed to have
what is electronegativity
measure of an atoms attraction for another atom’s electrons
what does the electronegativity scale range from
0-4
do metals have high or low electronegativity and why
low because metals are generally electron givers
do non metals have high or low electronegativity and why
high because generally non metals are electron takers
why is electronegativity useful
can use the difference between 2 electronegativites and to determine the type of bond
what is the bonding continuum
defines how and what compounds bond
what is the electronegativity of a covalent bond
less than 1.7
what is the electronegativity of an ionic bond
greater than 1.7
steps for lewis structures (covalent bonding)
1) determine total # of ve
2) determine central atom (one with the most bonding electrons
3) make bonds with single electrons
- make sure each atom has 8 ve although there are some exceptions
4) count the # of ve in drawing to make sure it is the same as step 1
steps for orbital/electron dot diagrams (ionic bonding)
1) show all electrons in an atom with numerical values
2) indicate # of protons in each atom
3) indicate which electrons are transferring to the non metal with an arrow
4) redraw with electrons placed in new spots
5) indicate if each atom is an anion or cation and their charge
+ means lost an electron
- means gained an electron
exceptions to the octet rule
- aluminium and boron only need 6 ve
- hydrogen only needs 2 ve
what are network solids
atoms or molecules held together by covalent bonds
steps for lewis structures (polyatomics)
1) follow same rules and for
cations: subtract # of electrons from total
anions: add # of electrons to total
steps for drawing VESPR shapes
1) determine total # of ve
2) determine central atom
3) draw lewis structure
4) determine VESPR shoe and draw
5) label slightly negative side
6) label polarity
7) label intermolecular forces
list of VESPR shapes
linear trigonal planar trigonal pyramidal tetrahydral bent
how to determine polarity
polar means the central atom is attatched to different atoms
non polar means the central atom is attached to the same atoms
exception to determining polarity
bent is always polar
trigonal pyramidal is always polar
