Metalic bonding and macromolecules

Question 1

define metallic bonding

Answer 1

metallic bond is the mutual electrostatic attraction between positively charged ions in a metal and the Sea of delocalised/mobile electrons

Question 2

what is the structure for metals

Answer 2

giant metallic latice

Question 3

what are the properties of metals?

Answer 3

1. high mp and bp
2. can conduct electricty in solid and molten state
3. ductile and malleable

Question 4

why are metals ductile and malleable?

Answer 4

Pure metals are malleable and ductile because the orderly layers of atom can slide over one another easily without disrupting the metallic bonds

Question 4

why do metals have high mp and bp?

Answer 4

metals gave giant metallic structure

strong electrostatic forces of attraction between positive ions and the Sea of delocalised electrons

large amount of energy is required to overcome the attraction metals

have a high melting and boiling point

Question 4

why can metals conduct electricity?

Answer 4

sea of delocalised electrons act as mobile charge carriers

Question 5

define alloys

Answer 5

mixture of a metal with one or more other element.

Question 5

What are macromolecules?

Answer 5

1. another covalent substance is called macromolecules.
2. polymers are macromolecules.
3. a polymer consists of many covalent molecules join together into chains of much larger molecules

Question 6

why are alloys harder and stronger than metals?

Answer 6

the main reason is different sizes of atoms in alloys.

the different sizes disrupts the ordinary arrangement of atoms and prevents the layers of atoms from sliding over each other easily when forces applied

Question 7

Give me examples of polymers.

Answer 7

silk, wool, rubber.

man-made polymers:
polyester, nylon, Plastics

Question 8

Properties of polymers.

Answer 8

1. no fixed mp or bp
2. insoluble in water, soluble in organic solvents
3. cant conduct electricity in any state (no mobile charge carriers)

Question 9

why do polymers have no fixed mp or bp?

Answer 9

• Polymers are usually solid at room temperature because of their large molecular size.
• They do not have a fixed melting point but soften over a range of temperatures.
• This is due to the variation in the size of polymer molecules.
• The weaker intermolecular forces are gradually overcome as temperature increases, causing the polymer to soften.