bonding- ionic+covalent+metallic

Question 1

what is ionic bonding?

Answer 1

strong electrostatic forces of attraction between oppositely charged ions held in a lattice.

Question 2

eg of an ionically bonded substance

Answer 2

NaCl

Question 3

How high are ionically bonded subtsances’ bp and melting point? why?

Answer 3

High - takes a lot of energy to break strong electrostatic forces of attraction between oppositely charged ions.

Question 4

Do ionic compounds conduct electricity?

Answer 4

Yes, when molten/in solution ad the ions are free to move and carry charge. They do not conduct electricity in solid.

Question 5

Do ionic compounds dissolve in water?

Answer 5

yes they do. water molecules are polar so part of the molecules have partially positive and partially negative charge . these charged parts pull ions away from the lattice, causing it to dissolve.

Question 6

what is covalent bonding?

Answer 6

when molecules form by sharing electrons - there is an electrostatic attraction between the nuclei and the shared electrons.

Question 7

how many electrons are shared in a double covalent bond?

Answer 7

4

Question 8

What is dative covalent bonding?

Answer 8

where one atom provides both electrons. they are represented by arrows.

Question 9

What is metallic bonding?

Answer 9

lattice of positive metal ions strongly attracted to a sea of delocalised electrons.Layers can slide over eachother- malleable

Question 10

does metallic compounds have high or low MP or BP?

Answer 10

Yes because there is a strong electrostatic force of attraction between the positive ions and negatively charged sea of delocalised electrons.

Question 11

does metallic compounds conduct electricity?

Answer 11

Yes as the delocalised electrons can move throughout the metal to carry charge.

Question 12

How does the strength of metallic bonds change across the periodic table?

Answer 12

—> increases
there is higher charge on metals so more delocalised electrons per ion…leading to a stronger electrostatic force of attraction between them.

Question 13

what is simple molecular covalent bonding?

Answer 13

strong covalent bonds between the atoms, weak van der waals forces between the molecules.

Question 14

Are there any lone pair of electrons in simple covalent bonds?

Answer 14

No - all electrons are involved in bonding

Question 15

can simple molecular covalent molecules conduct electricity? why?

Answer 15

No - all electrons are involved in bonding and arent free to move.

Question 16

do simple molecular substances have high or low mtp or bp? why?

Answer 16

Low- there are weak van der waals forces of attraction between the molecules which dont take much energy to overcome.

Question 17

describe macromolecular covalent bonding?

Answer 17

lattice of many atoms held together by covalent bonds.

Question 18

do substances with macromolecular covalent bonds have high mp or bp? why?

Answer 18

high, as it takes a lot of energy to overcome many covalent bonds.

Question 19

describe the structure of a diamond?

Answer 19

tetrahedral, each carbon atom bonded to 4 other carbon atoms

Question 20

describe the structure of graphite?

Answer 20

• macromolecular covalent
  -each carbon atom is bonded to 3 other so it is in layers
• weak VDW forces between layers so layers can slide over each other.
• one electron from each carbon is delocalised so can conduct electrcity.