chemical bonding (8.0-8.4)

Question 1

what is ionic bonding?

Answer 1

attraction between oppositely charged ions

Question 2

what is covalent bonding?

Answer 2

sharing of electrons

Question 3

what is metallic bonding?

Answer 3

free electrons hold metal ions together

Question 4

what is an octet?

Answer 4

eight electrons main group elements s^2p^6

Question 5

what is a lewis structure?

Answer 5

• counts electrons in the outer valance shell (s & p)
• draw one lewis dot for each valence electron around an atom
• draw up to four unpaired electrons, then pair additional electrons

Question 6

exceptions to lewis structure (transition metals)

Answer 6

• do. not necessarily follow the octet rule
• lose the valence s&p electrons, first then lose the d electrons necessarily for the given ion charge

Question 7

exceptions to lewis structure (main group metal)

Answer 7

lose electrons to reach lower noble gas congifuration

Question 8

exceptions to lewis structure (nonmetals)

Answer 8

gain electrons to reach higher noble gas configuration “octet”

Question 9

exception to lewis structure (hydrogen metals)

Answer 9

needs two electrons to reach 1s^2 closed shell for H- (duet)

Question 10

what is the equation for coulomb energy?

Answer 10

E=KQ1Q2/d

Question 11

what are properties of ionic substances?

Answer 11

• negative & positive ions arranged in a lattice
• held together by electrostatic attraction of opposite charges

Question 12

what is lattice energy?

Answer 12

the energy required to separate a solid ionic compound into its gaseous ions (endothermic)

Question 13

what are lattice energy trends?

Answer 13

• increases with a charge on the ions, and with smaller ionic sizes
• decreasing the size of the ion
• larger for ions with higher charges

Question 14

what is a covalent bond?

Answer 14

are atoms that share electrons. for covalent bonds to form the attractions must be greater than the repulsions
- molecular compounds are held together by covalent bonds

Question 15

what are electrostatic interactions in covalent bonds?

Answer 15

• attractions between electrons and nuclei
• repulsions between electrons and nuceli

Question 16

what is the number of bonds for nonmetals?

Answer 16

• the group number is the number of valence electrons
• to get an octet, like the nearest noble gas, in the simple covalent molecules for nonmetals, the number of bonds needed will be the same as the electrons needed to complete the octect

Question 17

what are lone pairs?

Answer 17

electron located on only one atom in a lewis structure

Question 18

what are bonding pairs?

Answer 18

two shared electrons in a lewis structure, represented by a line

Question 19

what are single bonds?

Answer 19

some atoms share only one pair of electrons

Question 20

what are double bonds?

Answer 20

two pairs need to be shared to reach & octect

Question 21

what are triple bonds?

Answer 21

three pairs are shared between the atoms

Question 22

what is bond polarity?

Answer 22

is the measure of how equally or unequally the electrons in a covalent bonds are shared

Question 23

what are nonpolar covalent bonds?

Answer 23

the electrons are shared equally. F2 (any diatomic element)

Question 24

what are polar covalent bonds?

Answer 24

one of the atoms attracts electrons to itself with a greater force HF or LiF

Question 25

what is electronegativity?

Answer 25

is the ability of an atom in a molecule to attract electron to itself
- increases from left to right (except to noble gas) from top to bottom

Question 26

what are polar covalent bonds?

Answer 26

when two atoms share electrons unequally. electrons tend to speed more around the more electronegative

Question 27

what is a dipole?

Answer 27

when two equal, but opposite charges are separated by distances a dipole forms