Particles Of Substances

Question 1

What are the two types of covalent structures

Answer 1

Molecular and network

Question 2

What are the particles in a covalent network structure

Answer 2

Atoms

Question 3

What are the particles in a covalent molecular structure

Answer 3

Molecules

Question 4

What are the particles in an ionic structure

Answer 4

Positive and negative ions

Question 5

What are the particles in a metallic structure

Answer 5

Positive metal ions

Question 6

What are the binding forces in covalent molecular structures

Answer 6

Covalent bonds

Question 7

What are the binding forces in a covalent molecular structure

Answer 7

Week intramolecular forces

Question 8

What are the binding forces in an ionic structures

Answer 8

Ionic bond

Question 9

What are the binding forces in a metallic metallic structure

Answer 9

Metallic bonds : forces between ions and delocalised electrons

Question 10

What are the properties of ionic compounds

Answer 10

• the electrostatic forces between positive and negative ions are very strong. It thus takes a large amount of energy to pull the ions apart. This mess that ionic compounds are solid at room temperature and have high melting points
• solid ionic compounds are unable to conduct electricity as the charged particles are not free to move. However, when a ionic compound is molten, the particles are free to move and act as charge carriers and can thus conduct electricity when molten
• they are hard and brittle. This is because when pressure is applied to an ionic solid, the layers of ions move and the like charged ions line up. The electrostatic repulsion causes the crystals to break

Question 11

What’s re the properties of covalent molecular substances

Answer 11

• the intermolecular forces between molecules in a covalent molecular compound are weak. This means that most have low melting points and are gasses at room temperature
• they do not conduct electricity
• solid molecular substances are soft–iodine crystals and bees wax

Question 12

What are the properties of covalent network substances

Answer 12

• Extremely high melting points as the bonds that are formed are strong. This means that they are solid at room temperature
• hard (exception – graphite)
• do not conduct electricity (exception – graphite)

Question 13

Properties of metallic substances

Answer 13

• conduct heat and electricity. This is because the delocalized electrons are free to move
• they are male able and ductile. They melt easily and can be flattened or drawn into wires since the forces between the metal ions and the delocalised electrons continues to hold metals together even under those conditions
• high density – this implies that the atoms are closely packed
• metallic lustre –the loosely bound electrons reflect frequencies of light.