Structure 2.1 (Ionic bonding)

Question 1

why do atoms form bonds?

Answer 1

the bond is to achieve a more stable electron configuration, occurs when the valence shell is completely filled

Question 2

Atoms with partially filled valence shells tend to:

Answer 2

Metals (left of periodic table) - lose electrons forming a cation
Non-metals (right of periodic table) - gain electrons forming an anions

Question 3

losing electrons

Answer 3

configuration becomes that of the nearest previous noble gas

Question 4

gaining electrons

Answer 4

configuration bevomes that of the nearest next noble gas

Question 5

ionic radius of cations

Answer 5

cations are smaller than their neutral atoms (fewer electrons = stronger pull)

Question 6

ionic radus of anions

Answer 6

anions are bigger than their neutral atom (more electrons = increased repulsion)

Question 7

ionic charges of groups 1,2,13,14,15,16,17,18

Answer 7

1 - lose one
2 - lose 2
13 - lose 3
14 - unlikely to form ions (due to costs of energy
15 - gain 3
16 - gain 2
17 - gain 1
18 - does not form ions (noble gas configuration already

Question 8

transition metals ionic charges

Answer 8

electrons fill 4s before 3d, but 4s electrons are lost first when forming cation, because both 4s and 3d electrons can be lost, transition metals have variable oxidation states they often form more than one ion

Question 9

Ionic bonding

Answer 9

the electrostatic attraction between oppositely charged ions, ionic compounds are electrically neutral

Question 10

naming binary compounds

Answer 10

1) cation comes first - same as electron name
2) anion comes second (ends with -ide)
3) transition metals use roman numeral for the cation charges

Question 11

polyatomic ions

Answer 11

made of more than one atom bonded covalently, overall charge involved.

Ammonium - NH4+
Hydroxide - OH-
Nitrate - NO3-
Hydrogen Carbonate - HCO3-
Carbonate - CO3(2-)
Sulfate - SO4 (2-)
Phosphate - PO4 (3-)

Question 12

naming ionic compounds with polyatomic ions

Answer 12

cation first, anion name is the full polyatomic ion name no ide.

Question 13

what affects the strength of electrostatic attraction between ions

Answer 13

charge and distance

Question 14

melting and boiling points

Answer 14

high melting and boiling points because of the strong electrostatic forces of attraction that require a considerable amount of energy to break into a liquid state or vaporize into a gaseous state

Question 15

electrical conductivity

Answer 15

Solid ionic compounds don’t conduct because ions are fixed. When molten, ions can move, so they conduct electricity and undergo chemical changes at the electrodes.

Question 16

solubility

Answer 16

Many ionic compounds dissolve in water because water pulls the ions apart and surrounds them (hydration). This releases energy. If this energy is enough to overcome the energy holding the ions in the solid lattice, the salt dissolves.

Question 17

brittleness

Answer 17

if someone presses the lattice on either side hard enough to budge, the negatives will be next to negatives so the lattice wont just bend but break due to the repulsion.

Question 18

solid state of ionic compound is in what structure

Answer 18

giant 3D lattice, not discrete molecules

Question 19

lattice enthalpy

Answer 19

measure of the strength of the forces between ions in an ionic solid

Question 20

the smaller the ion…

Answer 20

the greater the lattice enthalpy

Question 21

the greater the charge…

Answer 21

the greater the lattice enthalpy

Question 22

ionic bond formation is

Answer 22

exothermic