2.4 electrons, bonding and structure

Question 1

ionic bonding

Answer 1

electrostatic attraction between a positively charged metal ion and a negatively charged non-metal ion

Question 2

properties of ionic compounds

Answer 2

• high melting and boiling points
• do not conduct as solids
• conduct when molten
• soluble in water

Question 3

covalent bonding

Answer 3

strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 4

properties of simple covalent compounds

Answer 4

• low melting and boiling point
• liquids/gases at RTP
• do not conduct electricity

Question 5

properties of giant covalent compounds

Answer 5

• large lattices
• very strong covalent bonds
• high melting and boiling points
• do not conduct electricity

Question 6

dative covalent bonding

Answer 6

the bonding electrons in a bond are from one of the atoms

Question 7

metallic bonding

Answer 7

lattice of positive metal ions within a ‘sea’ of delocalised outer electrons

Question 8

metallic bonding properties

Answer 8

• high melting and boiling points
• high heat and electrical conductvity
• strong, malleable and ductile

Question 9

linear

Answer 9

2 BP
0 LP
180º

Question 10

trigonal planar

Answer 10

3 BP
0 LP
120º

Question 11

tetrahedral

Answer 11

4 BP
0 LP
109.5º

Question 12

trigonal bipyramidal

Answer 12

5 BP
0 LP
90º 120º

Question 13

octahedral

Answer 13

6 BP
0 LP
90º

Question 14

trigonal pyramidal

Answer 14

3 BP
1 LP
107º

Question 15

bent

Answer 15

2 BP
2 LP
104.5º

Question 16

trigonal planar

Answer 16

3 BP
2 LP
120º

Question 17

square planar

Answer 17

4 BP
2 LP
90º

Question 18

electronegativity

Answer 18

ability of an atom to attract the bonding electron in a covalent bond

Question 19

electronegativity depends on

Answer 19

1. the nuclear charge
2. distance between outer shells and the nucleus
3. level of shielding by other shells

Question 20

electronegativity trend

Answer 20

across a period and up a group increases (F most)

Question 21

intermolecular forces weakest -> strongest

Answer 21

induced dipoles < permanent dipoles < hydrogen bonding

Question 22

hydrogen bonding

Answer 22

dipole-dipole interaction between hydrogen and the lone pair of electrons on O/F/N

Question 23

permanent dipoles

Answer 23

the weak intermolecular forces of attraction that arise between permanently polar molecules.

Question 24

induced dipoles

Answer 24

induced dipole-dipole forces are weak intermolecular forces of attraction present between all atoms and all molecules. the random movement of electrons introduces a instantaneous dipole which induces a neighbouring molecule