Bonding

Question 1

Metallic bond

Answer 1

Electrostatic attraction between lattice of + metal ions and delocalised e-

Question 2

Giant

Answer 2

Type of structure in which there is a regular repeating pattern (lattice) of atoms/ions held together by strong chemical bonds

Question 3

Ionic bond

Answer 3

Electrostatic attraction between oppositely charged ions

Question 4

Covalent bond

Answer 4

Sharing of a pair of electrons between 2 atoms

Question 5

Ion

Answer 5

+ or - charged atom or covalently bonded group of atoms where number of e- is different form number of protons

Question 6

Polyatomic ion

Answer 6

Ion containing more than 1 ion

Question 7

Anion

Answer 7

-

Question 8

Cation

Answer 8

+

Question 9

Giant ionic lattice

Answer 9

3 dimensional structure of oppositely charged ions bonded together by strong ionic bonds

Question 10

Solubility

Answer 10

Measure of how well one substance dissolved into another

Question 11

Melting point

Answer 11

Temperature at which a solid becomes a liquid at a fixed pressure, usually standard pressure

Question 12

Metallic bond diagram

Answer 12

Write charge of ion in the circles
Draw electrons as e- (not circles)
Label ‘positive metal ion’ and ‘free moving delocalised electrons’
9 max
Regular pattern
Ions ‘in layers’, e- spread out
Match charge and number of e-

Question 13

Effect of metal group on strength

Answer 13

Higher group = more delocalised e- = more electrostatic attraction
(Stronger bond + higher mp)

Question 14

Octet rule

Answer 14

Full outer shells as ions

Question 15

Exception to + charge ions

Answer 15

Ammonium, NH+

Question 16

Drawing ions

Answer 16

Use []
Charge in superscript

Question 17

Covalent bonding occurs between…

Answer 17

Non-metallic elements
Molecules / compounds
Polyatomic ions

Question 18

Double bond

Answer 18

2 shared pairs in a double bond

Question 19

Dot Cross steps

Answer 19

1. Single bond line diagram
2. Actual bond lines - for valence
3. Replace line with dot+cross
4. Add electrons for each group number

Question 20

Dot Cross - Polyatomic Ions

Answer 20

1. Single lines
2. Add minus charges to outside atoms as *
3. Add correct bonds for valency ( * = 1 valence )
4. Replace lines with dot cross
5. Add electrons needed for groups. * as ▪️

Question 21

Dot Cross - Positive Polyatomic Ion

Answer 21

1. Draw molecules that it would separate into ( NH4 🟰 N + H )
2. Draw them as 1 = Polyatomic ion
3. Add [ ] and +- charge

Question 22

Dative Covalent Bond

Answer 22

Shared pair of electrons supplied by one atom only (two crosses/dots)

Question 23

Extended Octet

Answer 23

Some elements hold 8+ e- in outer shell , depending on the period .
Eg. 2 = shell 2 - holds 8
Eg. 3 = shell 3 - holds 18

Question 24

Single bond

Answer 24

Electrostatic attraction between 1 shared pair of electrons and the nuclei of the bonding atoms

Question 25

Exceptions to octet rule

Answer 25

1. Boron :
   - period 2
   - valence 3
   - BF3 - only has 6 outer e- but is stable

Question 26

Exception to octet rule 2 (covalent)

Answer 26

Beryllium forms covalent bonds with Chlorine - BeCl2
TiCl4

Question 27

properties of ionic compounds

Answer 27

• high MP & BP
• soluble in polar solvents only, like water. (not hydrocarbons - polar)
• conductive only as aqueous (when solid in fixed positions in giant ionic lattice)

Question 28

what does ionic bond strength depend on

Answer 28

smaller ions -> stronger ionic bonds
higher charge ion -> stronger

Question 29

what is the attraction in covalent bonds

Answer 29

electrostatic between shared pair e- and nuclei of bonded atoms.

Question 30

dative covalent bonds between …

Answer 30

atoms with vacant orbitals and atoms with lone pairs.

Question 31

what is a lone pair

Answer 31

pair of electrons not involved in bonding

Question 32

which period of elements can have more than 8 outer e- and why

Answer 32

they have access to the d sub-shell.

Question 33

what is Average bond enthalpy

Answer 33

measurement of covalent bond strength.