Unit 2

Question 1

ionic bond

Answer 1

transfer of electrons between metal and nonmetal. greater than 1.7 electronegativity between the atoms
brittle

Question 2

covalent

Answer 2

sharing of electrons between two nonmetals can be polar and nonpolar

Question 3

polar

Answer 3

unequal sharing of electrons (when it has a charge) 0.5-1.7

Question 4

nonpolar

Answer 4

equal sharing of electrons (symmetric) <0.5

Question 5

metallic bond

Answer 5

between metal atoms; attraction due to multiple metallic cations being attracted to a delocalized sea of valence electrons

can be pure, interstitial, and substitutional

Question 6

metal properties

Answer 6

good conductors of heat and electricity
malleable
ductile
lustrous
-> metal atoms lose electrons to form cations

Question 7

properties of covalent

Answer 7

• brittle
• poor conductors
• form anions by gaining electrons

Question 8

cations

Answer 8

positively-charged ions

Question 9

anions

Answer 9

negatively charged ions

Question 10

bond enthalpy

Answer 10

energy required to break a bond/ energy released when bond is formed.
-> greater radius = longer bond length
-> longer bond length = decrease in bond energy

Question 11

lattice energy

Answer 11

energy to separate ions in ionic compounds
-> larger charges = higher lattice energy
-> smaller raddii = higher lattice energy

Question 12

ionic solids characteristics

Answer 12

• high melting points and
• nonvolatile (reactive)

Question 13

sea of electrons

Answer 13

electrons move around and dont stay in one place
ionic radius decrease attraction increase

Question 14

alloys

Answer 14

mixtures of metals
interstitial
substitutional

Question 15

interstitial alloys

Answer 15

atoms added to metal are small and fit INBETWEEN metal atoms

Question 16

substitutional alloys

Answer 16

atoms added have similar radii as metal, replace atoms in the lattice

Question 17

LEWIS DIAGRAM BUILDING

Answer 17

1. count # of electrons
2. subtract # of electrons that were used for pairing
3. add remaining electrons as dots
4. look to add multiple bonds if not all atoms acheived octets
5. add remaining to central atom
6. add [] if it is an ion + the charge
7. look for formal charge so we have the best version of the lewis diagram (all must be 0 or have the charge on the most electronegative atom)

Question 18

formal charge

Answer 18

determines which lewis structure is most valid
-> count bonds as one electron

Question 19

VALID STRUCTURES

Answer 19

1. formal charge as close to 0 for all atoms
2. negative formal charge will be placed on most electroneg atom

Question 20

resonance structures

Answer 20

draw arrows between all models that signify the same thing
bond lengths are avg of bonds present ex : -1 = -1/2 and -1/2 on both of the side atoms (no brackets needed)

Question 21

VSPR theory

Answer 21

valence shell electron pair repulsion

Question 22

X–M–X

Answer 22

sp

Question 23

X–M-X-X

Answer 23

spp

Question 24

bond polarity

Answer 24

difference in electronegativity values of two elements

Question 25

properties of metals :

Answer 25

• lustrous
• Malleable
• Ductile
• good conductors of heat and electricity
  – metal atoms lose electroms to form cations

Question 26

nonvolatile

Answer 26

not reactive