Bonding-Types of Solids

Question 1

What are Ionic Substances Composed of?

Answer 1

Positive Cations, and Negative anions

Question 2

What are the forces holding ions together in ionic solids?

Answer 2

Electrostatic forces of attraction.

Question 3

Are ionic substances electrically neutral?

Answer 3

Yes as they have an equal number of positive and negative charges.

Question 4

Properties of ionic solids?

Answer 4

• High Melting Point
• Soluble in Polar solvents
• Conductive when ions are free to move (molten or aqueous)
• Very hard
• Brittle easily brake when force applied

Question 5

What are molecular substances

composed of?

Answer 5

Discrete molecules

Question 6

Forces holding molecules together in a molecular substance?

Answer 6

Weak Van der Waal forces of attraction.

Question 7

Properties of Molecular Substances?

Answer 7

• Low Melting Point
• Polar molecules dissolve in polar solvents, vice versa
• Do not conduct, no free to move charged particles
• Soft
• Solids Shatter

Question 8

What are intramolecular bonds?

Answer 8

Strong covalent bonds between atoms in a molecule

Question 9

What are intermolecular bonds?

Answer 9

Weak forces of attraction between molecules

Question 10

What do Lewis diagrams of molecules show?

Answer 10

Where covalent bonds are located and where lone pair electrons are located.

Question 11

What shape is a molecule with 4 regions of electron density, of which two are bonded?

Bond angles?

Answer 11

Bent

Question 12

Electronegativity is the measure of an atoms ability to?

Answer 12

Attract electrons to itself

Question 13

What atom on the periodic table is most electronegative?

Answer 13

Fluorine.

Question 14

If a molecule is polar it has a molecular….?

Answer 14

Molecular dipole. (Bond dipoles do

not cancel)

Question 15

Metals are found on what side of the periodic table?

Answer 15

Left hand side.

Question 16

What do metallic substances consist of?

Answer 16

Positively charged metal nuclei, surrounded by a ‘sea’ of delocalised electrons.

Question 17

Metals are held together by what?

Answer 17

Very strong, non-directional electrostatic forces of attraction between metal nuclei and nearby electrons.

Question 18

Are delocalised electrons free to move through the substance even when solid?

Answer 18

Yes

Question 19

Properties of Metals?

Answer 19

-High Melting Point.
-Not soluble
-Can conduct due to delocalised electrons
Malleable, and ductile- because of the nondirectional bonding between metal nuclei and delocalised electrons.

Question 20

What does ECN stand for?

Answer 20

Extended covalent networks- solids

Question 21

What do Covalent Networks consist of?

Answer 21

A large number of non-metal atoms covalently bonded together.

Question 22

What are the covalent network solids at NCEA level 2?

Answer 22

Diamond- Carbon
Silicon Dioxide- SiO2
Graphite- Carbon

Question 23

Properties of Covalent Network solids?

Answer 23

• Very High Melting Point
• Insoluble
• Conductive if delocalised electrons are present (graphite)
• diamond, and silicon dioxide very hard, graphic soft.

Question 24

What is different about graphite, compared to other ECN?

Answer 24

It consists of sheets of Carbon atoms, with strong intramolecular bonds between atoms, but weak intermolecular bonds between the sheets. Making it soft and slippery. It also has one delocalised electron on each atom, that is free to carry electrical current.