bonds between atoms

Question 1

Covalent bonds are weak.

True of false

Answer 1

False.

Covalent bonds are very strong

Question 2

Cl-Cl This shows the bonding for a chlorine molecule.

True or false?

Answer 2

True. Chlorine atoms form into pairs. Each Chlorine atom has 7 electrons its outer shell. When they bond, they each share an electron.
Draw a ‘dot and cross diagram’ for this.

Question 3

Covalent bonds allow sharing of electrons so that each atom has a complete outer shell.
True of false

Answer 3

True. Each atom ‘tries’ to complete its outer shell.

Draw ‘dot and cross’ diagram for water: H-O-H

Question 4

Metal atoms are bonded by covalent bonds.

True or False

Answer 4

False. Metal atoms are bonded by metallic bonding

Question 5

Electrons in the outer shell of metal atoms are ‘delocalised’
True or false?

Answer 5

True. Some of the outer electrons can move about. They become like ‘glue’ which holds all the atoms together. (electrostatic attraction)

Question 6

Metals have a giant regular structure.

True or false?

Answer 6

True

Question 7

Outer electrons in metal atoms are delocalised producing an arrangement of positive ions held together by electrostatic attraction.
Explain this statement.

Answer 7

When a metal atom ‘looses’ electrons it becomes positively charged (a positive ion). The delocalised electrons form a kind of ‘sea’ which washes round the positive ions. They provide a force of attaction.

Question 8

Metallic bonds are very strong.

True or false

Answer 8

True

Question 9

Delocalised electrons can move about?

True of false

Answer 9

True

Question 10

Why do metals have high melting and boiling points?

Answer 10

Atoms have strong metallic bonds