Structure And Bonding In The First 20 Elements

Question 1

What is Metallic bonding? And give account on its conductivity and M.P

Answer 1

• Metallic bonding is the attraction between the charged metal ions and the electrons.
• Metallic bonding consists of positive metal ions surrounded by a pool of delocalised electrons.
• As metallic bonding is a relatively strong attraction, metals typically have high melting points reflecting the energy required to overcome the strong metallic bonds.
• As the electrons are free to move, metals conduct electricity.

Question 2

What are the Metallic bonding elements?

Answer 2

• Li
• Be
• Na
• Mg
• Al
• k
• Ca

Question 3

Give an account of covalent network elements:

Answer 3

• Covalent network structures consist of many thousands of atoms joined together by covalent bonds.
• These structures have very high M.P as strong covalent bonds must be broken for the solid to melt.
• Examples include carbon (diamond and graphite), silicon and boron.

Question 4

Give an account of monatomic elements:

Answer 4

• The noble gases are monatomic elements as they consists of single atoms which are not bonded to neighbouring atoms.
• The monatomic elements have very low M.P as they are held together by weak LDF.
• As you descend the noble gases, the M.P increases as the LDF become stronger and this is due to the increased number of electrons.

Question 5

Give an account on covalent molecular elements:

Answer 5

• For all covalent molecular elements, the INTRAmolecular forces, the bonds within the molecule, are covalent.
• The INTERmolecular forces, those between the molecules, are the very weak LDF.
• Most of theses elements have relatively low M.P and B.P since only the weak LDP forces have to be broken to melt and boil them.